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Introduction to cellular radio - Page 1
Milestones in radio
Traditional mobile radio
Cellular network planning
Cells do overlap !
Cellular radio - why does it work?
Cellular design objectives
Introduction to cellular radio
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Introduction to cellular radio - Page 2
The Radio Story So Far
Radio communication started at the beginning of the 20th Century,with a handful of famous scientists making individual calls, sometimesacross large distances.
Land mobile communications as we know it started in 1921, with adespatch system used by the Detroit Police Department and was stillavailable to relatively few until the 1940s.
World War II stimulated the introduction of mobile communicationsbut until the development of the transistor in the 1950s; and smallreliable transceivers; relatively few people had experienced thefreedom radio communication provides.
The Bell Telephone Laboratories were responsible for thedevelopment of land mobile systems and eventually the publiccellular system in North America, however Scandinavia introducedthe first public cellular system in 1981 with the NMT system.
Now as we start the 21st Century, millions of people will be makingsimultaneous conversations over personal wireless telephones. Thishas only been made possible by using cellular radio techniques.
1901 1st transatlantic radio transmission
1904 John Ambrose Fleming invented the diode
1919 Dr Frank Conrad (Westinghouse in USA)
1919 H.J. Round (Marconi Wireless Telegraph
UK)
1921 Detroit police department
1948 Transistor announced by Bell Telephone
1981 NMT (Nordic Mobile Telephone) system
1991 First commercial GSM system
Milestones in radio
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Introduction to cellular radio - Page 3
Before Cellular Radio
Before cellular radio, personal communication over large areas reliedon powerful transmitters flooding the coverage area withtransmissions. The main disadvantage of this was that very highpower transmitters were required, and the number of simultaneousconversations was limited to the number of channels available.
This type of system limits the capacity (i.e.. number of simultaneousconversations) as the same channels cannot be used again in anadjacent area. A guard band is required of at least 4:1 (guard bandto coverage area) before the same channel frequency can be re-used.
With radio spectrum a valuable resource, lateral thinking was neededand a method that restricted the power and hence coverage areaswas required if mobile communication was to compete with land-linesin quantity.
(Note that in some countries 120 watt mobile radios are still used forpoint to point communications by the emergency services).
Coverage area Guard band
Traditional mobile radio
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Introduction to cellular radio - Page 4
Cellular Concept
The cellular radio concept relies on many transmitters (or basestations) each covering a limited area or cell. Each cell is allocated aset of channels. These channels cannot be re-used by adjacent cellsotherwise radios would interfere, but careful frequency planningallows the pool of channels to be re-used after a guard band.
The smaller the cells, the more often frequencies can be re-used, andhence the greater the number of conversations in a given graphicalarea. In fact the network is designed so that cell sizes are relative tothe expected number of subscribers in the area; so in an urban areacells are small and in a rural area large.
Sophisticated planning of so called microcells and picocells are nowemployed where cell diameters may be as small as 1km.
Note that a maximum cell radius of about 35 km is possible for GSM:where hand portable coverage is required, cells are considerablysmaller.
Cellular network planning
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Introduction to cellular radio - Page 5
Cells do Overlap
Almost all the theoretical explanations of cellular radio show cells asbeing honeycomb shaped. This is useful for planning purposes. butin reality local topography distorts the uniform shape.
For seamless cellular coverage, overlaps need to occur and networkplanners ensure that cells produce patterns that allow large enoughoverlaps for hysterisis if a mobile moves from one cell to another.
The use of omni directional and tri-sectored cell patterns is importantfor efficient use of infrastructure.
Cells do overlap !
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Introduction to cellular radio - Page 6
Cellular Radio - Why Does it Work?
Emitted RF power limits the range of a standard mobile radio. In anarea with few high buildings coverage up to around 50 km radius ispossible with a vehicle mounted radio. Hand portable radios with thisrange are cumbersome and would require large batteries.
Cellular radios are able to operate by communicating with the nearesttransmitter, or base station, and transferring seamlessly from one toanother.
A relatively limited amount of the frequency spectrum is available forpersonal wireless communications. Cellular systems re-use thisspectrum efficiently by planning for predicted subscriber capacity.
Cellular radios are carefully controlled to produce just enough powerat an allocated frequency to ensure quality communication. Thisability to change power and frequency without the user being awaremakes the cellular system far more sophisticated than traditionalmobile radios.
Cellular radio-why does it work ?
Seamless coverage without high power transmitters
Frequency re-use
Virtually unlimited capacity
Smart mobile terminals - controlled by the network
Frequency agilePower control
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Introduction to cellular radio - Page 7
Cellular Design Objectives
Cellular radio was always intended to provide a radio system for themass market. It was designed to provide good quality portablecommunications at an affordable price.
Speech quality had to be similar to the wired network and no specialtechnical knowledge was required to make calls.
Although initially the infrastructure costs are high, cellular has thepotential of offering affordable costs to a variety of users.
Roaming between different areas and virtually nation-wide coveragewas very desirable.
If phones were to be accepted by the mass market the size andbattery life must be acceptable.
New services, equivalent to those on the wired network must bepossible.
Cellular design objectives
Good speech quality
Easy to use
Low operational costs
Roaming between territories
Acceptable size and battery life
New services and facilities
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Introduction to cellular radio - Page 8
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Introduction to GSM - Page 1
Introduction to GSM
Why GSM ?
History of GSM
GSM standards
GSM & its derivatives
Services of GSM
GSM - not just voice
SIM cards
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Introduction to GSM - Page 2
Why GSM ?
Analog cellular systems were introduced in the early 1980s and comein many different technical standards. There are many differentstandards throughout the world, some variants based on existingnetworks.
GSM was initially introduced to provide a single digital standardacross Europe. This system has also been adopted in other parts ofthe world and is now regarded by many as the global cellularstandard.
The GSM standard brings many benefits to end users and networkoperators. For example roaming is now possible throughout manyparts of the world: this means that people can travel from one countryto another and still make and receive calls. There is no need for anyspecial equipment or arrangements; using the same GSM phone.The demand for mobiles is now huge and this is driving prices down.Test equipment also benefits form a common standard and can bethe same from one country to the next.
TACS
C-NETZ
AMPS
NMT-900
E-TACS
NMT-450
E-AMPS
RC 2000N-AMPS
Why GSM ?
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Introduction to GSM - Page 3
History of GSM
In the mid 1980s a group called Groupe Speciale Mobile was formed
to produce a next generation standard that would replace thenumerous European analog cellular systems in use. It was seen asmore than just a cellular system; it was designed to be compatiblewith the future telecommunications systems, particularly ISDN(Integrated Services Digital Network).
In 1987 a group of countries stated they would participate in the GSMsystem and would cooperate in 1991 by signing a MoU(Memorandum of Understanding). This initial group of signatorieswas only 18. It has evolved tenfold to become well over 180 by 1996and is still growing.
By the early 1990s well over 100 sets of recommendations (over5000 pages) had been produced by working with ETSI (EuropeanTelecommunication Standards Institute) to define all aspects of theGSM system.
In 1991 a formal type approval specification had been agreed for allmobile stations to conform to and later that year the first publicsystem went into operation.
Since then further recommendations have been agreed to provide asecond phase of mobiles. GSM standards continue to develop andnew features are being added on a continuous basis.
History of GSM
1982 Groupe Speciale Mobile formed
1987 MoU formed
1990 Technical committees produced over 100 CTRs
1991 Phase 1 recommendations
1995 Global System for Mobile Communication
1995 Phase 2 recommendations
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Introduction to GSM - Page 4
GSM standards
To ensure that GSM succeeded, 124 channels in the 890 - 960 MHzband were defined to be exclusively for GSM. The MoU membersworked to a common goal and allocated these frequencies in theircountries.
As more members joined from countries outside Europe, it wasrealised that the original GSM frequencies would not be sufficient. Anadditional band was added, providing a further 50 channels. Thisband is referred to a E-GSM (Extended GSM) and falls below theoriginal channels.
In many countries these channels are already allocated to analogcellular service and will gradually be converted to GSM.
GSM standards
P-GSM
E-GSM (Phase 2 frequency range)
E P(50ch) (124ch)
MS - BTS (uplink)
880.2 MHz 890.2 MHz 914.8 MHz
BTS - MS (downlink)
925.2 MHz 935.2 MHz 959.8 MHz
EP
(50ch) (124ch) Frequency
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Introduction to GSM - Page 5
GSM had been so successful in some developed countries that morechannels were allocated in the 1800 MHz band. A delta specification,based on GSM signalling and protocols was developed and is nowbeing implemented in Europe and many other parts of the worldwhere the frequencies are available and demand requires theadditional capacity.
In North America a number of bands allocated in the 1900 MHzregion have been auctioned to potential network operators and somehave deployed another variant of GSM using similar signalling andprotocols to GSM.
Further systems based on GSM are now planned for privatesystems.
A number of global and regional satellite systems that have beenproposed also use a significant proportion of the GSM standards.
DCS - 1800
GSM & its derivatives
MS - BTS (uplink) BTS - MS (downlink)
1710.2 1784.8MHz 1805.2 1879.8MHz
PCS - 1900
1850 1910MHz 1930 1990MHz
What Next?
GSM & Its Derivatives
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Normal telephone service is enhanced by the provision of emergency
calls using standard procedure in any country i.e.. 911 or 999 or 112.Emergency calls are possible even when a subscriber has beenbarred from making regular calls and even when no SIM is fitted.
Supplementary ServicesGSM supports an extremely comprehensive list of supplementary services.
The list includes:-
Call Forwarding Unconditional
Mobile Subscriber Busy
No Reply
Mobile Not Reachable
Call Barring Outgoing
Outgoing International
Outgoing International except to Home Country
Incoming
Incoming when roaming abroad
Call Waiting
Call Hold
Three Party Service
Advice of Charge
The full list of supplementary services is extensive and includes some which arevery novel. Some of these services may not be available initially, and introductionmay vary from network to network.
Services of GSM
Emergency Calls
Call Forwarding
Call Barring
Call Waiting
Advice of Charge
Services of GSM
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GSM - not just voice
As well as traditional speech communication a number of otherservices are provided in the GSM specification. Data transmission of9600 b/s is possible and plans to reach higher data rates are underdevelopment. Because data uses the original capabilities of GSM,error correction can be made even under fading conditions.
The short message service allows the transmission of 160 alphanumeric characters to and from a subscriber. This service providesan advanced paging service as messages may be received duringconversations. If the one is switched off or out of the area covered byGSM, the message is stored in the network and offered to thesubscriber when they reappear on the network.
Applications such as traffic announcements can be broadcast to allphones in a cell or geographical area using the cell broadcast feature.
These features will become some of the key competitivedifferentiators between networks.
GSM - not just voice
Data Transmission
Facsimile Group III
Short message service (SMS)
Cell Broadcast
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How GSM works: a mobiles perspective - Page 1
A typical GSM network
Channel structure
Registration / location update
Registration information
The structure of an IMEI
The structure of an IMSI
Mobile idle
Call setup
Power control
Timing advance
Handover
IMSI detached
How GSM works: a mobiles perspective
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A Typical GSM Network
To understand how GSM works, consider what a normal GSMsystem consists of.
The phone, referred to as the MS (Mobile Station) needs a SIM(Subscriber Identity Module) to make regular communication with thenetwork.
The phone communicates to the network of BTSs (Base TransceiverStations) deployed over the coverage area.
Each BTS is connected to a BSC (Base Station Controller) which is inturn connected to a MSC (Mobile Switching Centre).
The MSC provides connection to the PSTN=Public SwitchedTelephone Network). The MSC holds important information that isneeded to ensure communication can take place.
Information held at the MSC provides details of whether phones arelikely to be switched on, details of which visiting phones may beoperating on the network. Also whether the subscriber is valid (thatthe bills have been paid!)
MSCMSCBTS
BTS
BTS
BTS
BTS
BTS
BTS
BSCBSC
PSTN
SIM
A typical GSM network
MS
Databases
of
users
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Channel structure
Each cell uses one or more of the pool of channels allocated to thenetwork. So as an example a GSM 900 network allocated half of thetotal 124 channels would have 62 channels.
The 62 channels need to be divided up to ensure adjacent cells donot use the same channel. In some urban cells there may be 15 or16 channels to a BTS. Rural cells may only require one channel.
Each channel is divided into 8 time slots. One or more is used forcontrol and the remainder for traffic.
0 1 2 3 4 6 7 0
Channel structure
5
Control
Traffic
Traffic
Traffic
Traffic
Traffic
Traffic
Traffic
Control
Traffic
7
Time
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Registration / location update
When a radio is switched on it needs to let the network know where itis to enable calls to be received. As the subscriber moves around,there is a need for the phone to update its location. Thisregistration/location updating is performed automatically andaccording to certain rules set by the network. (There is no need toconstantly update phone locations as the network would soonbecome overloaded and no useful information would be gained).
GSM radios can also de-register on power down to allow the networkto know that calls are not possible.
(Note: different networks use different strategies for locating mobiles.Some may require the phone to update every time it moves into anew cell : this almost guarantees location immediately. Othernetworks may allow phones to move several cells before requiring anupdate : finding a phone may then take longer, because a number ofcells will need to be paged before locating the mobile).
Registration / location update
I am here
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IMSI - International Mobile Subscriber Identity
IMEI - International Mobile Equipment Identity
- Mobile Class
SIM - Subscriber Identity Module.
- PIN Personal Identity Number
- PUK Personal Unblocking Key
Registration information
Registration Information
The IMSI (International Mobile Subscriber Identity) is information heldon the SIM (Subscriber Identity Module) and can be thought of as thesubscribers unique number, which is translated to provide atelephone number by the network.
The IMEI (International Mobile Equipment Identity) is information heldon the phone and can be thought of as the electronic serial number.This number holds information about the phone, such as class andtype.
The SIM holds information for the subscriber including a PIN number,which is used for additional security. With the PIN function enabled,
a 4 to 8 digit number must be entered before calls can be made. Ifthis is incorrectly entered 3 times in a row , the SIM automaticallyblocks. To unblock the SIM an 8 digit PUK (personal unblocking key)must be entered.
(Note an Emergency call can be placed in the absence of a SIM:onlythe IMEI is sent).
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The Structure of an IMEI
The IMEI, ranges of which are allocated upon the granting of typeapproval, include the mobile TAC (Type Approval Code) and the FACFinal Assembly plant code, and includes a serial number which isunique for each unit of a given type.
FACTAC SERIAL NUMBER SPARE
TYPEAPPROVED
(6 digits) (2 digits) (6 digits) (1 digit)
The structure of an IMEI
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The Structure of an IMSI
An IMSI (International Mobile Subscriber Identity) consists of threeparts: the MCC ( Mobile Country Code), identifying a country; theMNC (Mobile Network Code), identifying a PLMN (Personal LandMobile Network) within this country; and the MSIN (MobileSubscriber Identification Number) identifying a subscriber within thisPLMN, using no more than 10 digits.
MCC MCN MSIN
(3 digits) (2 digits) (10 digits or less )
The structure of an IMSI
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The Racal Instruments 6103 produces the screen above, after M.S.registrations. As well as the IMSI and IMEI, the mobile class isdisplayed.
The 6103 can be configured to simulate any country or network andthe BCCH (Broadcast Control Channel) can be selected by theoperator if desired.
6103Main Menu
Parameters
Results
Memory
Card
Unsync
Mode
Single
SequencesSelf Tests /
System
Offsets
Test
Radio
Multimode
Tests
System
15 JAN 1996 11:24:57
Offsets : OFFResults: OFFStd : INT13GPIB : 20
Status : RR Connection Released RXLEV :RXQUAL :
Mobile Class
IMSI 2349178
IMEI 23456789
TMSI
3
BCCH ARFCN 121
BCCH level -30.5 dBm
MCC
MNC
Mobile and System Information
Place a call to start Functional Tests
234
91
2349178
23456789
121
-85.0
Place a call to start Functional Tests
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Mobile Idle
Once the radio has registered, it monitors the strongest cell controlchannel. Via this channel it can be paged and therefore receive callsfrom the system. Usually the mobile in this state will be designed toconsume the minimum of power, non essential circuits are turned off.If the mobile moves into a new cell area it may need to re-register inthat area.
In order to test a mobile, it is often useful to force the mobile toperform a location update at the start of every test. This can be donein a number of different ways, one method being to ask the phone toregister on switch on.
Mobile idle
Paging channel
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Call setup
Calls can be set up by the user dialling out or the radio being pagedby the network. ie mobile originated or base station originated.
Calls are setup on control channel timeslots and then transferred to atraffic channel / timeslot. (The process actually requires severalmessages as authentication and the various layers of communicationare established).
Note: In a rural cell, there may be only one channel used forcombined control and traffic. One timeslot is used to send controlinformation and the remainder are available for traffic.
In busier cells a number of channels may be used for controlinformation. The traffic will be shared appropriately.
Call setup
Call request
Go to channel x / slot y
O.K.. Im ready
Go ahead & talk
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Power control
During conversation the base station periodically measures the powerit receives from the mobile. It can then instruct the mobile to adjustits power, via a control channel as it moves in a cell. This helpsreduce the overall level of RF in a cell and leads to less chance ofone phone interfering with others.
With GSM, the mobile also measures received signal strength andquality. This information is passed back to the base station so it canadjust its power also. Power control for GSM is much finer than thaton analog systems.
GSM mobiles can adjust their power in 2dB steps from +13dBm
(20mW) to a maximum of +39dBm/8W for a class 2. In practice mostmobiles are class 2 (max. power = +39dBm/8W) and most handportables are class 4 (max. power = +33dBm/2W).
Phase II GSM specifications define four new power levels (PL16-PL19) to allow for even smaller cells and hence better frequency re-use.
DCS1800 and PCS1900 phones use different power levels : see thetables in the section: Useful data.
Go to
Power level 3
Traffic
Power control
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The Racal 6103 performs an automatic test that demonstrates thepower levels and provides the measured value and the error in dB.Any results that do not meet those specified are highlighted for theuser.
Where test leads or fixtures introduce attenuation, an offset can beadded to the calculation to compensate. The offset is shown to beON in the screen above.
Test Status Fail : Measured Values Exceed Test Limits
Mobile Power Level ---
TCH Slot 4TCH ARFCN HOP
TCH Level -85.0 dBm
1
2
3
4
5
6
Requested Measured
dBm
dBm
dBm
dBm
dBm
dBm
+27.2
+19.6
+21.8
+12.9
+7.9
+119
Offsets : ONINT 13
01 JAN 1996 12:00:00Running : Power Levels/Steps
Results : OFFStd :GPIB : 20
Status : Call Connected MT RXLEV : 21RXQUAL : 0
Error
dB
dB
dB
dB
dB
-0.2
-3.4
+2.8
-2.1
-3.1
+4.9
dB
Step Number
dBm
dBm
dBm
dBm
dBm
dBm
Test
Information
Edit
Parameters
Repeat
Test
EXIT
8
10
12
14
16
18
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Timing advance
As a mobile moves around in a cell, the transmission time may getshorter or longer. In order for the mobile burst to arrive at the BTS inits allocated timeslot. The BTS orders the mobile to advance itstiming.
GSM mobiles can adjust their timing by up to 63 bits in one bit steps.There are guard periods at the end of every standard burst, so smallerrors in timing can be tolerated.
(Note: The maximum cell radius for GSM is approximately 35km (22miles) as the propagation time to and from a mobile is approximately
0.5km per bit. 63 bits allows a propagation time of 233s ;approximately 35km).
Adjust Timing
advance to 63 bits
Traffic
Signals must arrive atBTS at correct time BTS
Timing advance
Traffic
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Handover
What differentiates a cellular radio system from basic mobile radio is thecapacity for handover. As the user travels he will move from one cell toanother. When appropriate, the conversation is handed over to the nextbase station. This process should be transparent to the user as asimultaneous speech path is set up on the new BTS before the mobilechanges channel / timeslot.
In the GSM system the mobile provides information to the BTS bymeasuring the level of the adjacent cells during the idle timeslots. Thisinformation is reported to the BTS at least every 30 seconds so thenetwork can determine when a handover is needed and to where.
(Note: The required sensitivity for phones are - 102dBm handportableGSM
- 104dBm other GSM
- 100dBm DCS1800 (class 1& 2
- 102dBm DCS1800 (class 3)
- 102dBm All PCS 1900
Handover
Call gets handed over to suitable BTS
Strong signal
Weak signal
Speech
Speech
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IMSI detached
GSM phones send a signal (IMSI detached) to the network to informthem they are being switched off. This saves the network paging forphones that are not able to receive calls.
Note: It can also be useful when testing a phone as the signal can beused to provide a test system indication that the phone testing hasfinished.
IMSI detached
Off button
Im switching off
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How GSM works :the bigger picture and what needs testing
GSM the air interfaceMSK modulationGMSK modulationBurst Timing
TX powerUseful part of burstBurst structureTDMAFrequency hoppingImproved Tolerance to FadingSpeech codingVocoder technologyError protectionDigital vs AnalogAuthenticationEncryption
MeasurementsPhase trajectorySensitivityBit errors and frame erasureVoice loopbackOther measurementsReceiver measurementsBurst profile measurement
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The GSM air interface provides a number of new concepts, acronymsand opportunities for measuring equipment. Fortunately the GSMspecification is well defined in the recommendations.
GMSK (Gaussian Minimum Shift Key) modulation is used to transmitRF information.
RF information is sent as bursts of data, timeshared with other userson the same channel (TDMA) Time Division Multiple Access.
Speech is digitised and then coded to reduce the actual number ofbits sent over the air.
Frequency hopping is used to improve performance in a multipathfading environment
Encryption is used to ensure security & speech privacy.
GSM - the air interface
GMSK modulation
TDMA & frame structure
Frequency hopping
Digitised speech
Encryption
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MSK Modulation
Speech, data and signalling information is transmitted over the air asdigital information (i.e. 1s and 0s).
These 1s and 0s are modulated on to an RF carrier using GMSKmodulation.
The process initially involves changing the phase of the RF carrier. A0 will produce a phase change of -90 deg and a 1 +90 deg. This isMSK (minimum shift keying).
One advantage of MSK is that the RF Amplitude is constant; this isless likely to produce distortion if their are any non-linearities in thesystem.
MSK modulation
I
Q 0
1
t
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GMSK modulation
The MSK modulated signal is effectively passed through a Gaussianshaped filter to reduce the bandwidth of the signal. This is essential ifchannel spacing is to be kept to a minimum.
GSM makes use of 0.3GMSK. This means that the BT (bandwidth:bitrate) is 0.3. This design ensures that a channel spacing of 200 kHz ispossible.
Note: BT is bandwidth to bit period factor
B= bandwidth of the Gaussian filter
T= bit period (i.e.1/t = bit rate)
GMSK modulation
Phase
Phase modulation
Time1 0 000 1111 000
MSK
GMSK
time
phase
steps
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Burst Timing
The phone will transmit its speech in one of eight time frames. This isreferred to as TDMA (Time Division Multiple Access).
Because it may be sharing a single carrier with several other users,the timing of the transmitted burst must be controlled accurately. Thebase station will advise the phone to advance its burst to take intoaccount the different propagation time over the air. This is doneonce initial syncronisation is made.
To ensure proper syncronisation, Access bursts are sent initially toensure that data is not sent in an adjacent timeslot. Access burstsare shortened by 60 bits and are sent by the phone until the BTS has
instructed it to advance its transmissions.There is a guard period equivelant to 8.25 bits between each burst(68.25 bits for access bursts), each speech burst has 3 tail bits at thebeginning and end which carry 000 information and allow time forthe burst to reach full power before sending meaningful data.
Burst timing
147 useful bits
1 timeslot
Guard time
8.25 bits
Commands to Advance (up to 63 bits)
time
Previous
burst
Next burst
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Tx Power
As well as the timing of the burst, its shape is very important. Thereis a power template defined in the GSM specifications that sets limitsfor its shape and relative amplitude with time.
The flatness of the portion carrying the data must fit within a +/-1dBwindow. The rising and falling edges must fit limits that ensure theydo not produce ringing and yet still allow enough time to convey thedata.
Tx power
-70dB
-30dB
1dB
4dB
-1dB
0 3 147 bits
t
not to scale
6
-6dB
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The above screen from the 6103 shows the entire length of the powerprofile on a speech burst. The screen also displays the absolutepower level, also the minimum and maximum power over the usefulpart of the burst.
All bursts must fit the power profile defined in GSM Rec 11.10. Ifpower ramps up or down too fast, interference might be caused in theadjacent channel and cause interference to other users.
If the Ramp is too slow, then data may be lost from the burst oradjacent timeslot interference may occur.
It is possible to examine the useful parts of the power burst using the6103. Both the rising and falling edge may be examined in moredetail. The top of the burst may also be displayed in more detail
Audio
Speech
MultiMode : Power ProfileBER
Phase
Summary
EXIT
Modulation
Spectrum
Error
Mode
TCH ARFCN
TCH Slot
TCH Level
62
dBm-85.0
4
MS Power
7
More...
Input Power
Min
30.273
Max
30.32830.285
Current
dBm dBm dBm
15 JAN 1996 11:24:57
Offsets : OFFResults: OFFStd : INT13GPIB : 20
Status : Call Connected MT RXLEV : 23RXQUAL : 0
10
Bits
0
-10
-20
-30
-40
0 20 40 60 80 100 120 140
dB
-50
-60
-70
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Burst structure
Although there are some exceptions, the majority of bursts are madeup of Speech information, a syncronisation sequence and 3 tail bits ateach end.
The speech information is coded in a variety of different ways, andwill be explained later. It occupies 116 bits.
The syncronisation sequence is often referred to as a trainingsequence or mid-amble. It consists of 26 bits of predefined data, thatcan be decoded and then used as a reference for timing andequalization.
The 3 tail bits at either end serve as guard bits between other time
slots.
Burst structure
Speech
Information
Speech
Information
Sync
Mid-
Amble
Sync
Mid-
Amble000000 000000
Mobile Transmit Burst - TCH
Speech
Information
Speech
Information
3 58 26 3 bits58
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TDMA
There is a delay of 3 time slots between the downlink from the BTS
and the uplinkfrom the phone. This allows a single synthesiser to beemployed in the phone as the transmit and receive timeslots do notcoincide. It also reduces the need for complex duplex filters
The phone is also able to monitor other channels during the idle slots.during this time the radio monitors the signal strength of the adjacentchannels.
TDMA
11 22 33 44 55 66 77 00
Base Station Transmit, Mobile Receive
66 77 00 22 33 44 55
Mobile Transmit
Adjacent Cell
Monitoring
11
1
Offset 3 slots
66
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Improving tolerance to fading
Frequency hopping is a way of improving the tolerance to the effectsof multipath fading. This is where reflections of the main signalcombine to mix destructively: producing a signal fade.
Because this fading is frequency dependent, a fade on one channelfrequency may produce constructive mixing on another frequency.
By frequency hopping over a number of channels, the effects offading are reduced to a minimum, this means that the majority of timefading will not be apparent as error correction can still function.
Improving resistance to fading
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Frequency hopping
All mobiles have the capability of frequency hopping although it maynot always be used.
Frequency hopping can be switched on and off by the network.Some networks may switch on the hopping in parts of the networkwhere multipath is a problem.
In hopping mode the phone will switch to a different ARFCN(Absolute Radio Frequency Channel) after each burst according to apredefined sequence.
Frequency hopping
P
tf
ARFCN
Channel
Frames
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Frequency hopping
The 6103 has the ability to hop like the network. The hopping patterncan be defined by the user and switched on and off as required.
Test : SensitivityAccept
CancelOffsets : On10 MHz Results: Off Std:GPIB : 20
T.A. : RXLEV: RXQUAL:
14 DEC 1995 14:12:44
Parameter
Range : 0 to 31
TCH ARFCN
TCH Slot
Hopping
Encryption
Pass/Fail Threshold
Initial Level
Final Step Size
Test Pattern
Sample Time
FER Limit
Class Ib BER Limit
Mobile Power Level
Value
90
1
-102.0
15
Default
62
4
7
OFF OFF
OFF OFF
-90.0 -90.0 dBm
0.50 0.50 dB-102.0 dBm
10 10 s
1 1
0.200 0.200 %
0.410 0.410 %
Class II BER Limit 2.440 2.440 %
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The speech goes through two distinct processes before it ismodulated onto the RF carrier.
First the analog speech is sampled at a rate of 8 kbits / s. Eachsample produces 13 bits of information: a total data rate of 104kbits/s. If fhis were sent directly to the modulator the occupiedbandwidth required would be enormous.
A speech coder or vocoder is used to reduce the number of bits thatneed to be sent. Vocoders are designed to produce acceptableintelligent transfer of speech information, while minimising the amountof data sent. There are a number of vocoders available today, andmore are being proposed with enhanced capability.
Speech coding
Speech Speech
coder
Analog to
digi tal
converter
Error Protection
13 bit /samples
@ 8k bit rate
=104 kbits/s
104 kbits/s
reduced to
13 kbit/s
13 kbits/s
increased to
22 kbit/s
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The original vocoder used for GSM is a full-rate 13kbit/s vocoder: Ahalf rate vocoder is also available, producing a rate of 6.5kbit/s.Others are also in use, such as an enhanced full rate vocoder in theUS.
The GSM full rate coder reduces the 104 kbit/s rate down to aneffective 13 kbits/s. How it does this is beyond the scope of thisdocument, but put simply, the vocoder breaks down the speech in away that only the important elements of the speech are sent, allowingthe information to be decoded to an acceptable level. For examplesilence in the signal would not require any data to be sent.Reductions of 80% can be achieved by this process.
Note that all this processing does introduce a delay of approximately65ms and can be tricked: try sending your favourite music trackacross the network and you may well be disappointed.
Vocoder technology
full rate
vocoder104 kbits /s
sampled speech
13 kbits /s
coded speech
half rate
vocoder104 kbits /s
sampled speech
6.5 kbits /s
coded speech
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So far the coded speech data would be unprotected from anyinterference or impairements in the system, so error protection isadded.
Here the data is grouped into class Ia bits, Ib bits and class II bits.The class Ia bits are the most important and are given parityprotection by adding 3 parity bits. They are then added to class Ibbits and convolutionally coded to provide further correction anddetection. The class 2 bits are left unprotected.
This brings up the 13k bits/s data to 22.8 kbits/s.
If a class 1a bit cannot be corrected, the entire frame will be replacedby silence, as these bits could cause disturbing sounds ifreconstituted incorrectly.
Error protection
Class 1a bits = very important = add parity bits
Class 1b bits= quite important = code with Class 1a
Class 2 bits = not important = no correction
13 kbits/s rate increased to 22 kbits/s
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Although this whole process seems very complex and cumbersome,it produces the best compromise for transfer of speech to anacceptable level in a radio network.
Compared to analog systems, digital systems tend to have no betterperformance in good coverage areas, yet they out-perform them atextremes of range.
The graph above shows how the GSM system, with all its processingpower, will maintain a conversation far beyond an analog TACSsystem.
Digital vs Analog
0
1020
30
40
50
60
70
80
90
100
-80 -85 -90 -95 -100 -105 -110 -115 -120 -125
Analog
Digital
Receive level (dBm)
Speech quality
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Every time the phone registers or makes a call, an authenticationprocess takes place.
A random number is sent from the base station. This number iscombined with another number (or key) called a Ki.
The Ki is a number held on the SIM that is unknown to the user. Thecombination of the Ki, the random number and the A3 algorithmproduces a number over the air that the network can test.
This process ensures that the system is very secure, as every call setup requires an acknowledgement before the call can be processed.This method also ensures that the Ki is never sent over the air.
The network can also assign a TMSI (Temporary Mobile SubscriberIdentity) ensuring the mobiles true identitiy is not used for
subsequent call set ups.Encryption is not always used, it can be switched on and off by thenetwork.
Encryption provides a secure way of further encoding the speech, toprevent eavesdropping over the air. Another algorithm (A8)generates a cipher key (Kc) from the random number, which is thenused to encrypt all the following data.
Authentication
random number
(Ki & random number) A3 algorithm
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Measurements
As with most tranceivers, measurement are made on the transmitter,receiver and the speech path.
The phase relationship of a signal in GSM is very important. Any testequipment must be able to measure both peak and RMS phaseerrors and in order to perform any diagnostics, look at the relationshipduring the burst.
Measurements
Phase Trajectory
Tx Power
Sensitivity
Voice Loopback
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Phase Trajectory
The modulation accuracy is measured by comparing the actual phasetrajectory with the theoretical trajectory over several bursts.
Large deviations will result in bit errors, so a fairly tight limit is placedon the phone. Less than 20 degrees peak and less than 5 degreesRMS is required for the phone to meet specification.
Mobile frequency is adjusted in the mobile by synchronising from theFCCH (Frequency Correction CHannel) on the BCCH (BroadcastControl Channel). The error must be less than 0.1ppm.
Phase Trajectory
Bits
Phase
Phase Error
Frequency
Error
Ideal PhaseActual Phase
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To measure the sensitivity of a phone, the GSM specificationprovides a test loopback mode in all phones. This can be invoked byusing a test SIM and an instruction over the air.
The test SIM provides the loopback facility which turns all receivedsignals back onto the transmitter path so that bit errors can bemeasured. The loopback is provided after the channel coding anddoes not include the vocoder.
The Racal 6103 produces a pseudo-random data pattern that ismodulated by the internal signal generator, the phone is put intoloopback mode by sending the correct command and then sensitivitycan be measured. This is done by reducing the level of the RFsignal and measuring the errors. The bit error rate can be used todetermine the sensitivity of the phone.
Note: Some phones use the spare slots to monitor the controlchannel and maintain frequency control, so the 6103 provides asimulated signal during these slots, so that the phone still apparentlysees a control channel.
Sensitivity
Signal
Generator
Signal
Generator
Data
Pattern
Generator
Data
Pattern
Generator
Measuring
Receiver
Measuring
Receiver
BER
Software
BER
Software
test SIM
Rx data
= Tx
Test System
2nd
Signal
Generator
2nd
Signal
Generator
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Because some bits are given different levels of protection againsterrors, it is not straight forward to just measure bit error rate on allreceived bits.
RBER (Residual Bit Error Rate) is defined as the BER in all goodframes. A good frame is defined as one where the parity in the class1a bits were not received in error.
Where errors are received in class Ia bits, frames are erased andreplaced eirther data that is predicted from previous frames, or insevere cases muted audio.
Measurement of the number of frames erased or FER (FrameErasure Rate) can be made.
Bit errors and frame erasure
BER for class Ia, Ib & II
RBER for class Ib & II
FER (Frame Erasure Rate)
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The above diagram shows the three measurements of FER, Class Iband Class II bit error rates. Where limits are exceeded, the resultsfield is highlighted.
Freq. Offset
Test Pattern
8
+120
More...
EXIT
Hz
Timing Adv.
24 bits
LimitsMultiMode : BER
Clear
Min/Max
FER
Samples
50
CIb 6600
CII
Min
1.29
2.29
2.29
Max
3.53
3.53
3.53 3900
Current
2.50
2.50
2.50 %
%
%
%
%
%
%
%
%
15 JAN 1996 11:24:57 Burst
ALL
Offsets : OFFResults: OFFStd : INT13GPIB : 20
Status : Idle RXLEV : 23RXQUAL : 0
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Receiver measurements
During a conversation, the mobile makes 2 measurements on thecurrent physical traffic channel (TCH). These two measurements areRXLEV, the level of the traffic channel and RXQUAL, the quality ofthe traffic channel (determined from the bit error rate).
There is also time for the phone to make measurement on up to 6neighbouring cells to determine if there is a better channel.
RXLEV must be within: +/-4dB at levels from -110 to -70 dBm
and +/-6dB at levels from -70 to -48 dBm.
Receiver measurements
RXLEV measurement of the RF signal strength
RXQUAL measurement of the bit error rate
Phone can measure up to 6 neighbour cells
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Receiver test results
Producing an accurate signal from the test equipment allows themeasurement produced by the phone to be compared and any errorsnoted.
The effect of having poor measurement by the phone could producedropped calls on the network.
The above screen makes this test very simple as the expected andmeasured values are displayed side by side with an errorcalculation.
Events Ratio
FER %0 0.000
CIb %0 0.000
CII %
Samples
50
6600
3900 11 0.282
Running : Receiver Test
Test Status PASS
Mobile Power Level 7
TCH ARFCN HOP TCH Slot 4
TCH Level -102.0 dBm
Measurement
Test
Information
Edit
Parameters
Repeat
Test
EXIT
15 JAN 1996 11:24:57
Offsets : OFFResults: OFFStd : INT13GPIB : 20
Status : Call Connected MT RXLEV : 22RXQUAL : 0
Expected Measured Error
8.5 (-102.0 dBm) 6.0 (-104.5 dBm) -2.5RXLEV :
1.0 (0.282 %) 0.0 (0.141 %) -1.0RXQUAL :
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Multimode : voice loopback
The 6103 has a number of tests that allow subjective assessment ofthe phones audio paths. One test is the Voice loopback. This testcan be selected manually or included in an automatic test sequence.
In the case of multimode the RF parameters can be viewed while thelooped back voice is monitored.
Phase
Error
MultiMode : Voice Loopback
EXIT
Voice Loopback
Speak into mouthpiece to assess mobile's performance.
Summary
Modulation
Spectrum
Power
Profile
BERTCH ARFCN
62
TCH Level
dBm-85.00
TCH Slot
4
MS Power
2
More...
15 JAN 1996 11:24:57
Offsets : OFFResults: OFFStd : INT13GPIB : 20
Status : Call Connected MT RXLEV : 23RXQUAL : 0
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The 6103 is able to put the phone into conversation mode and thencommand it to change to all power levels. The main RF port on the6103 is able to measure all power levels and then compare theresults with the defined standards.
Timing advance can be excercised either manually, by setting anadvance or by using the automatic test included.
A variety of impairements can be added during the RF testing suchas doppler shift, hopping and with a second 6103 or signalgeneraotor, co channel and adjacent channel rejection.
The availability of Fax and Data services on GSM presents a new set
of testing problems. Probably the most important requirement is toprove the correct function of the services under varying signalconditions, but above all is must be easy to use.
Other measurements
Power Steps
Timing Advance
Protocol Registration, Authentication
Call Set up
Handover
Encryption Doppler Shift
Fax and Data
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Multimode:Summary
For faultfinding, a comprehensive set of measurements is providedon one screen. Limits are shown as arrowheads and the bar graphschange colour if a limit is exceeded.
The update of the screen makes this multmode a very helpful;screen for diagnostics or phones.
When any parameters are changed, the 6103 automaticallygenerates the necessary protocol, making it very simple to use.
Freq. Offset
Test Pattn
1
0
More...
EXIT
Hz
Timing Adv.
0 bits
LimitsMultiMode:Summary 15 JAN 1996 11:24:57 Burst
ALL
Offsets : OFFResults: OFFStd : INT13GPIB : 20
Status : Call Connected MT RXLEV : 23RXQUAL : 0
5 %0.00C lass II BER 0
RXQUAL : 0 (0.0% : 0.2 %) RXLEV : 23 (-88 : -87 dBm)
31.08 Hz
3.35 Deg
28.02 dBmInput Power 23
RMS Ph Err 0
Peak Ph Err 0
Freq. Err -200
Timing Offset bits-0.29
35
200
10
40
Power Prof ile Pass Mod. Spectrum ---
9.99 Deg
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6103 Mobile test set
The 6103 is an easy to use, fully integrated Test Set optimized formaintenance and servicing of GSM, DCS1800 and PCS1900 mobiletelephones.
It has a comprehensive modulation analyser for alignment anddiagnosticsand has fast measurement capability with integrated testsequences.
The large, bright LCD display provides graphic and numeric displays.
In addition to speech testing cell broadcast and point to point shortmessage service testing is included. The no button start test is theultimate for simplicity of operation.
6103 Mobile test set
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The Racal Instruments 6103 addresses fax and data testing byemulating the GSM network right up to the far end terminal. Thisallows a high degree of flexibility and also allows a number of faxcombinations to be tried.
For data calls, files can be transferred from the instruments memorycard or from an external PC/device via an RS232 port. Data can betransferred in either transparent or non-transparent mode at 2400,4800 or 9600 baud.
For fax calls the 6103 uses industry standard modem commandswhich allows it to interface to a PC running commonly available faxpackages.
6103
Mobile
6103
PC or equivalent
PC or Fax
Hayes Modem
RF
MEMORY
CARD
256k
Memory Card
Fax and data testingFax and data testing
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6103 test set - interfaces
As standard, the 6103 comes equipped to provide results in a numberof ways. Control is provided by the GPIB interface.
The instrument also supports a form of BASIC. Using this language itis possible to create test programs with custom tests, limits andprintouts.
6103 Test Set - Interfaces
61036103
GPIB
RS232
Parallel Printer
2 x PCMCIA SlotsTest sequences
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Phase 2 type approval
This type approval system consists of 2 6103 Digital Radio Test Setscontrolled by a PC.
To provide the rapid and coherent introduction of Phase 2, the GSMMoU required the developement of a low cost, Stand Alone Testerbased upon off-the-shelf hardware. The tester had to allow forconformance testing of mobile stations and support over 150 GSM11.10 test cases, written in the TTCN (Tree and Tabular CombinedNotation) test specification language which is used ofr the definitionof Abstract Test Suites (ATS) under international standard ISO 9646
Part 3.
Phase 2 type approval
GSMGSMTESTTEST
7 8 9
65
3
4
21
0 #*
0252 625
TTCN Results
2 x 6103
6103
6103
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Cray systems PC controller
The RF outputs of these two devices are combined and applied to themobile under test, with the test results presented on the PC Controlleror to networked systems.
The Stand Alone Tester is an ideal test solution for a variety of users,from GSM test houses for the performance of formal type approvalaccreditation testing, to network operators and manufacturers ofmobile equipment.
Operators will also use the Stand Alone Tester to examine mobilestations which are perhaps giving an unexpected response to thenetwork. This will help these organisations pinpoint problems on thenetwork and/or discover operational difficulties with certain models ofmobile telephone, thereby improving the service to users.
Cray systems PC controller
Man Machine InterfaceMan Machine InterfaceMan Machine Interface
Operating System - WindowsOperating System - WindowsOperating System - Windows
TestTest
ControllerControllerTTCNTTCN
CompilerCompiler
PC HardwarePC HardwarePC Hardware
TTCN
Input
Library
User
Control
Test
Equipment
Analysis
& Report
Software
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How GSM works: a BTSs perspective and what needs testing - Page 1
Elements of the GSM Network
Test requirements
Production testCommissioning and installation
Live testing
What does the 6113 do ?
Typical test requirements
6113 applications
How GSM works: aHow GSM works: aBTSsBTSsperspective andperspective and
what needs testingwhat needs testing
BTSBTS
BSCBSC
U or Air interface
A-bis
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Before discussing base station testing, its important to understandthe basic elements of the system.
The BTS (Base Station Transceiver) is responsible forcommunicating with the mobiles over the radio interface.
The BTS lacks the intelligence to manage the calls: this isperformed by the BSC (Base Station Controller). Thecommunication between the BTS and the BSC is an ISDN compatible2.048 Mbit/s (E1) or 1.544 Mbit/s (T1) link. To control the BTS, theBSC uses manufacturer specific commands on this link. This is theA-bis interface.
The connection from the BSC to the PSTN is completely standardand allows more regular telecom links to be used.
Elements of the GSM NetworkElements of the GSM Network
MSC
(Switch)
MSC(Switch)
BTSBTSBSCBSC
PSTN
U or Air interface
A-bisA
2.048Mb/s or 1.544Mb/s
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Throughout the life of a BTS it will need to be tested in different ways.
During R&D traditional test equipment can be used, however forprotocol development a protocol analyzer or an interface emulator isrequired.
During production and installation the other elements of the networkare not present, hence A-bis emulation is advantageous.
Once commissioned some form of in-service testing is required.
Test requirementsTest requirements
Research & DevelopmentResearch & Development
Production & Factory TestProduction & Factory Test
Installation & CommissioningInstallation & Commissioning
Field Service & OptimizatioField Service & Optimizationn
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How GSM works: a BTSs perspective and what needs testing - Page 5
When commissioning base stations, it is very likely that the A-bis linkis not available. Even if it were the control of the BTS would still becumbersome.
A-bis control allows the BTS to be tested in isolation and can evenallow on-air trials with test network signals.
6113
6113
Commissioning andCommissioning and
installationinstallation
BSCA-bis RF
X
X
X
X
XXXX - BTS
GSM, DCS1800 or PCS1900
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Once installed there is a great reluctance to take a BTS out of servicesimply to test it. Live testing offers a slightly more limited, butconvenient, method of routine testing.
In order to access the correct channels and ensure consistent results,the test equipment could emulate a mobile and set up a live call.
The A-bis connection can still be used if receiver bit error rates are tobe measured.
Live testingLive testing
BSC RF
6113
6113
XXXX - BTS
GSM, DCS1800 or PCS1900
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The 6113 meets the requirements of GSM recommendations andprovides an independent evaluation of the RF performance of theBTS.
Test times are remarkably short: often the code download to the BTSmay take longer than the test.
By keeping records of the BTS performance, degradation can bemonitored and corrective action made before it gets too serious.
When new network roll out times are measured in months rather
than years, fast authoritative testing is essential.
What does the 6113 do ?What does the 6113 do ?
bIt verifies performance to GSM
recommendations (11.20, 05.05 etc.)
bIndependent evaluation of RF performance
bReduces BTS commissioning times
bImproves the BTS roll out rate
bIt reduces BTS downtime during faultfinding
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The above shows the typical range of parameters that networkoperators and manufacturers would test. The requirements are verysimilar to a mobile. The main difference is that with a mobile thecontrol is transmitted over the air interface. The BTS requires controlfrom the A-bis.
Typical test requirementsTypical test requirements
Receiver
Bit error rate (BER)
RACH sensitivity
TCH Absolute sensitivity
Timing advance
Rx level
Encryption
Rx quality
Functional
A-bis link tests
Code download
Configure BTS
Reset BTS
Special functions
Transmitter
Cell control channel
Bit error rate (BER)
Phase error
Frequency error
Modulation spectrum
Power
Power steps
Power profile
Power control
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Racal Instruments 6113 digital radio test set, has been designed toprovide a test capability in all of the above scenarios.
6113 applications6113 applications
61136113
BSC
A-bis
BTS
RF
61136113
61136113
61136113
A.I.M.E.
BOSSA-bis ControlA-bis Monitor
R&D and System Test
Base station On airService System
Installation andCommissioning
System faultdiagnosis
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GLOSSARY OF TERMS & ABBREVIATIONS
ARFCN AAbsolute RFRFCChannel NNumber. A number in the range1 to 124 (GSM) or 512 to 885 (DCS 1800) whichdefines the absolute radio frequency channel number.
AGCH AAccess GGrant CHCHannel
BA BBCCH AAllocation. The radio frequency channelsallocated in a cell for BCCH transmission.
BCC BBase Station CColour CCode
BCCH BBroadcast CControl CHCHannel
BCCH_FREQ_NCELL Frequency of the RF carrier on which the BCCH of aneighbouring cell is transmitted.
BER BBit EError RRatio
BFI BBad FFrame IIndicator
BS_AG_BLKS_RES The number of blocks on each common controlchannel reserved for access grant messages.
BSIC BBase Transceiver SStation IIdentity CCode
BS_PA_MFRMS The number of multiframes between two transmissionsof the same paging message to MSs of the samepaging group.
BTS BBase TTransceiver SStation
Burst A period of modulated carrier less than one timeslot.The physical content of a timeslot.
CA CCell AAllocation. The radio frequency channelsallocated to a particular cell
CAT CCell AAllocation TTable
CBCH CCellBBroadcast CHCHannel
CCH CC
ellCC
ontrolCC
hannel
CCCH CCommon CControl CHCHannel
CCCH_GROUP Group of MSs in idle mode.
CELL Geographical area within which a defined set ofchannels is provided.
CELL_BAR_ACCESS Cell access barred parameter.
CELL_RESELECT_HYSTERESIS The RXLEV hysteresis required for cell reselection.
CEPT CConference of EEuropean PPosts & TTelecommunications
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Class lA, lB, ll Classification of speech encoder bits depending on thedegree of protection needed. Class lA and Class lBbits have protection; Class ll bits have no protection.Error detection is performed on Class lA bits.
DAI DDigital AAudio IInterface
DTX DDiscontinuous TTransmission. Means of saving batterypower (e.g. in HPUs) and reducing interference byautomatically switching the transmitter off when nospeech or data are to be sent.
ESN EElectronic SSerial NNumber
ETSI EEuropean TTelecommunications SStandards IInstitute
FACCH FFast AAssociated CControl CHCHannel
FCCH FFrequency CCorrection CHCHannel
FER FFrameEErasure RRate
GMSK GGaussian MMinimum SShift KKey
GPIB GGeneral PPurpose IInterface BBus
GSM GGlobal SSystem for MMobile communications
HPU HHand PPortable UUnit
HSN
IMEI
HHopping SSequence NNumber
IInternational MMobile EEquipment IIdentity
IMSI IInternational MMobile SSubscriber IIdentity
ISDN IIntegrated SServices DDigital NNetwork
ITA IInterim TType AApproval
Kc Cipher Key Sequence
Ki Subscriber Authentication Key
LAI LLocation AArea IIdentity
MAHO MMobile AAssisted HHand OOver
MAIO MMobile AAllocation IIndex OOffset
MAT MMobile AAllocation TTable
MIN MMobile IIdentity NNumber
MMI MMan MMachine IInterface
MS MMobile SStation
MSC MMobile SSwitching CCentre
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MSK MMinimum SShift KKeying
MS_TXPWR_MAX_CCH Maximum allowed transmitted RF power for MSs toaccess the system until commanded otherwise.
PCH PPaging CHCHannel
PID PProtocol IDIDentifier
PIN PPersonal IIdentification NNumber
PLMN PPublic LLand MMobile NNetwork
PLMN_PERMITTED PLMN permitted for handover purposes.
RACH RRandom AAccess CHCHannel
RAND Random number used during Authentication.
RBER RResidual BBit EError RRate
RPE-LTP RRegular PPulse EExcitation - LLong TTerm PPrediction. Themethod used to of code and decode speech for theoriginal GSM vocoder.
RXLEV RReceived Signal LEVLEVel parameter. A measure of themean received signal level.
RXLEV_ACCESS_MIN The minimum RXLEV at a MS for access to a cell.
SACCH SSlow AAssociated CControl CChannel
SACCH_TF SSlow AAssociated CControl CChannel - TTraffic FFull Rate
SAPI SService AAccess PPoint IIndicator
SDCCH SStand Alone DDedicated CControl CHCHannel
SCH SSynchronisation CHCHannel
SIM SSubscriber IIdentity MModule
SMS SShortMMessageSService
SRES SSignature RESRESponse
TCH TTraffic CHCHannels. Channels that carry user speech ordata.
TDM TTime DDivision MMultiplexing
TDMA TTime DDivision MMultiple AAccess
TMSI TTemporary MMobile SSubscriber IIdentity
TN TTimeslot NNumber
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Useful Data - GSM P-2
E-GSM CHART 2 -- UPLINK (Mobile To Base Station)
CHANNELNUMBERS
UPLINK FREQUENCIES(MHz)
0 890.0001 - 5 890.200 890.400 890.600 890.800 891.0006 - 10 891.200 891.400 891.600 891.800 892.00011 - 15 892.200 892.400 892.600 892.800 893.00016 -20 893.200 893.400 893.600 893.800 894.00021 - 25 894.200 894.400 894.600 894.800 895.000
26 - 30 895.200 895.400 895.600 895.800 896.00031 - 35 896.200 896.400 896.600 896.800 897.00036 - 40 897.200 897.400 897.600 897.800 898.00041 - 45 898.200 898.400 898.600 898.800 899.00046 - 50 899.200 899.400 899.600 899.800 900.000
51 - 55 900.200 900.400 900.600 900.800 901.00056 - 60 901.200 901.400 901.600 901.800 902.00061 - 65 902.200 902.400 902.600 902.800 903.00066 - 70 903.200 903.400 903.600 903.800 904.00071 - 75 904.200 904.400 904.600 904.800 905.000
76 - 80 905.200 905.400 905.600 905.800 906.00081 - 85 906.200 906.400 906.600 906.800 907.00086 - 90 907.200 907.400 907.600 907.800 908.00091 - 95 908.200 908.400 908.600 908.800 909.000
96 - 100 909.200 909.400 909.600 909.800 910.000101 - 105 910.200 910.400 910.600 910.800 911.000106 - 110 911.200 911.400 911.600 911.800 912.000111 - 115 912.200 912.400 912.600 912.800 913.000116 - 120 913.200 913.400 913.600 913.800 914.000121- 124 914.200 914.400 914.600 914.800
975 - 979 880.200 880.400 880.600 880.800 881.000980 - 984 881.200 881.400 881.600 881.800 882.000985 - 989 882.200 882.400 882.600 882.800 883.000990 -994 883.200 883.400 883.600 883.800 884.000
995 - 999 884.200 884.400 884.600 884.800 885.000
1000 - 1004 885.200 885.400 885.600 885.800 886.0001005 - 1009 886.200 886.400 886.600 886.800 887.0001010 - 1014 887.200 887.400 887.600 887.800 888.0001015 - 1019 888.200 888.400 888.600 888.800 889.0001020 - 1023 889.200 889.400 889.600 889.800
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Useful Data - GSM P-3
DCS 1800 CHART 1 -- DOWNLINK (Base Station To Mobile)
CHANNEL NUMBERS
DOWNLINK FREQUENCIES(MHz)
512 - 515 1805.2 1805.4 1805.6 1805.8
516 - 520 1806.0 1806.2 1806.4 1806.6 1806.8521 - 525 1807.0 1807.2 1807.4 1807.6 1807.8526 - 530 1808.0 1808.2 1808.4 1808.6 1808.8531 - 535 1809.0 1809.2 1809.4 1809.6 1809.8
536 - 540 1810.0 1810.2 1810.4 1810.6 1810.8541 - 545 1811.0 1811.2 1811.4 1811.6 1811.8546 - 550 1812.0 1812.2 1812.4 1812.6 1812.8551 - 555 1813.0 1813.2 1813.4 1813.6 1813.8556 - 560 1814.0 1814.2 1814.4 1814.6 1814.8
561 - 565 1815.0 1815.2 1815.4 1815.6 1815.8
566 - 570 1816.0 1816.2 1816.4 1816.6 1816.8571 - 575 1817.0 1817.2 1817.4 1817.6 1817.8576 - 580 1818.0 1818.2 1818.4 1818.6 1818.8581 - 585 1819.0 1819.2 1819.4 1819.6 1819.8
586 - 590 1820.0 1820.2 1820.4 1820.6 1820.8591 - 595 1821.0 1821.2 1821.4 1821.6 1821.8596 - 600 1822.0 1822.2 1822.4 1822.6 1822.8601 - 605 1823.0 1823.2 1823.4 1823.6 1823.8606 - 610 1824.0 1824.2 1824.4 1824.6 1824.8
611 - 615 1825.0 1825.2 1825.4 1825.6 1825.8616 - 620 1826.0 1826.2 1826.4 1826.6 1826.8621 - 625 1827.0 1827.2 1827.4 1827.6 1827.8626 - 630 1828.0 1828.2 1828.4 1828.6 1828.8631 - 635 1829.0 1829.2 1829.4 1829.6 1829.8
636 - 640 1830.0 1830.2 1830.4 1830.6 1830.8641 - 645 1831.0 1831.2 1831.4 1831.6 1831.8646 - 650 1832.0 1832.2 1832.4 1832.6 1832.8651 - 655 1833.0 1833.2 1833.4 1833.6 1833.8656 - 660 1834.0 1834.2 1834.4 1834.6 1834.8
661 - 665 1835.0 1835.2 1835.4 1835.6 1835.8
666 - 670 1836.0 1836.2 1836.4 1836.6 1836.8671 - 675 1837.0 1837.2 1837.4 1837.6 1837.8676 - 680 1838.0 1838.2 1838.4 1838.6 1838.8681 - 685 1839.0 1839.2 1839.4 1839.6 1839.8
686 - 690 1840.0 1840.2 1840.4 1840.6 1840.8691 - 695 1841.0 1841.2 1841.4 1841.6 1841.8696 - 700 1842.0 1842.2 1842.4 1842.6 1842.8701 - 705 1843.0 1843.2 1843.4 1843.6 1843.8706 - 710 1844.0 1844.2 1844.4 1844.6 1844.8
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Useful Data - GSM P-5
DCS 1800 CHART 3 -- UPLINK (Mobile to Base Station)
CHANNEL NUMBERS
UPLINK FREQUENCIES(MHz)
512 - 515 1710.2 1710.4 1710.6 1710.8516 - 520 1711.0 1711.2 1711.4 1711.6 1711.8521 - 525 1712.0 1712.2 1712.4 1712.6 1712.8526 - 530 1713.0 1713.2 1713.4 1713.6 1713.8531 - 535 1714.0 1714.2 1714.4 1714.6 1714.8
536 - 540 1715.0 1715.2 1715.4 1715.6 1715.8541 - 545 1716.0 1716.2 1716.4 1716.6 1716.8546 - 550 1717.0 1717.2 1717.4 1717.6 1717.8551 - 555 1718.0 1718.2 1718.4 1718.6 1718.8556 - 560 1719.0 1719.2 1719.4 1719.6 1719.8
561 - 565 1720.0 1720.2 1720.4 1720.6 1720.8566 - 570 1721.0 1721.2 1721.4 1721.6 1721.8571 - 575 1722.0 1722.2 1722.4 1722.6 1722.8576 - 580 1723.0 1723.2 1723.4 1723.6 1723.8581 - 585 1724.0 1724.2 1724.4 1724.6 1724.8
586 - 590 1725.0 1725.2 1725.4 1725.6 1725.8591 - 595 1726.0 1726.2 1726.4 1726.6 1726.8596 - 600 1727.0 1727.2 1727.4 1727.6 1727.8601 - 605 1728.0 1728.2 1728.4 1728.6 1728.8606 - 610 1729.0 1729.2 1729.4 1729.6 1729.8
611 - 615 1730.0 1730.2 1730.4 1730.6 1730.8616 - 620 1731.0 1731.2 1731.4 1731.6 1731.8621 - 625 1732.0 1732.2 1732.4 1732.6 1732.8626 - 630 1733.0 1733.2 1733.4 1733.6 1733.8631 - 635 1734.0 1734.2 1734.4 1734.6 1734.8
636 - 640 1735.0 1735.2 1735.4 1735.6 1735.8641 - 645 1736.0 1736.2 1736.4 1736.6 1736.8646 - 650 1737.0 1737.2 1737.4 1737.6 1737.8651 - 655 1738.0 1738.2 1738.4 1738.6 1738.8656 - 660 1739.0 1739.2 1739.4 1739.6 1739.8
661 - 665 1740.0 1740.2 1740.4 1740.6 1740.8666 - 670 1741.0 1741.2 1741.4 1741.6 1741.8671 - 675 1742.0 1742.2 1742.4 1742.6 1742.8676 - 680 1743.0 1743.2 1743.4 1743.6 1743.8681 - 685 1744.0 1744.2 1744.4 1744.6 1744.8
686 - 690 1745.0 1745.2 1745.4 1745.6 1745.8691 - 695 1746.0 1746.2 1746.4 1746.6 1746.8696 - 700 1747.0 1747.2 1747.4 1747.6 1747.8701 - 705 1748.0 1748.2 1748.4 1748.6 1748.8706 - 710 1749.0 1749.2 1749.4 1749.6 1749.8
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Useful Data - GSM P-6
DCS 1800 CHART 4 -- UPLINK (Mobile to Base Station)(Continued)
CHANNEL NUMBERS
UPLINK FREQUENCIES(MHz)
711 - 715 1750.0 1750.2 1750.4 1750.6 1750.8716 - 720 1751.0 1751.2 1751.4 1751.6 1751.8721 - 725 1752.0 1752.2 1752.4 1752.6 1752.8726 - 730 1753.0 1753.2 1753.4 1753.6 1753.8731 - 735 1754.0 1754.2 1754.4 1754.6 1754.8
736 - 740 1755.0 1755.2 1755.4 1755.6 1755.8741 - 745 1756.0 1756.2 1756.4 1756.6 1756.8746 - 750 1757.0 1757.2 1757.4 1757.6 1757.8751 - 755 1758.0 1758.2 1758.4 1758.6 1758.8756 - 760 1759.0 1759.2 1759.4 1759.6 1759.8
761 - 765 1760.0 1760.2 1760.4 1760.6 1760.8766 - 770 1761.0 1761.2 1761.4 1761.6 1761.8771 - 775 1762.0 1762.2 1762.4 1762.6 1762.8776 - 780 1763.0 1763.2 1763.4 1763.6 1763.8781 - 785 1764.0 1764.2 1764.4 1764.6 1764.8
786 - 790 1765.0 1765.2 1765.4 1765.6 1765.8791 - 795 1766.0 1766.2 1766.4 1766.6 1766.8796 - 800 1767.0 1767.2 1767.4 1767.6 1767.8801 - 805 1768.0 1768.2 1768.4 1768.6 1768.8806 - 810 1769.0 1769.2 1769.4 1769.6 1769.8
811 - 815 1770.0 1770.2 1770.4 1770.6 1770.8816 - 820 1771.0 1771.2 1771.4 1771.6 1771.8821 - 825 1772.0 1772.2 1772.4 1772.6 1772.8826 - 830 1773.0 1773.2 1773.4 1773.6 1773.8831 - 835 1774.0 1774.2 1774.4 1774.6 1774.8
836 - 840 1775.0 1775.2 1775.4 1775.6 1775.8841 - 845 1776.0 1776.2 1776.4 1776.6 1776.8846 - 850 1777.0 1777.2 1777.4 1777.6 1777.8851 - 855 1778.0 1778.2 1778.4 1778.6 1778.8856 - 860 1779.0 1779.2 1779.4 1779.6 1779.8
861 - 865 1780.0 1780.2 1780.4 1780.6 1780.8866 - 870 1781.0 1781.2 1781.4 1781.6 1781.8871 - 875 1782.0 1782.2 1782.4 1782.6 1782.8876 - 880 1783.0 1783.2 1783.4 1783.6 1783.8881 - 885 1784.0 1784.2 1784.4 1784.6 1784.8
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Useful Data - GSM P-7
PCS 1900 CHART 1 -- DOWNLINK (Base Station To Mobile)
CHANNEL NUMBERS
DOWNLINK FREQUENCIES(MHz)
512 - 515 1930.2 1930.4 1930.6 1930.8516 - 520 1931.0 1931.2 1931.4 1931.6 1931.8521 - 525 1932.0 1932.2 1932.4 1932.6 1932.8526 - 530 1933.0 1933.2 1933.4 1933.6 1933.8531 - 535 1934.0 1934.2 1934.4 1934.6 1934.8
536 - 540 1935.0 1935.2 1935.4 1935.6 1935.8541 - 545 1936.0 1936.2 1936.4 1936.6 1936.8546 - 550 1937.0 1937.2 1937.4 1937.6 1937.8551 - 555 1938.0 1938.2 1938.4 1938.6 1938.8556 - 560 1939.0 1939.2 1939.4 1939.6 1939.8
561 - 565 1940.0 1940.2 1940.4 1940.6 1940.8566 - 570 1941.0 1941.2 1941.4 1941.6 1941.8571 - 575 1942.0 1942.2 1942.4 1942.6 1942.8576 - 580 1943.0 1943.2 1943.4 1943.6 1943.8581 - 585 1944.0 1944.2 1944.4 1944.6 1944.8
586 - 590 1945.0 1945.2 1945.4 1945.6 1945.8591 - 595 1946.0 1946.2 1946.4 1946.6 1946.8596 - 600 1947.0 1947.2 1947.4 1947.6 1947.8601 - 605 1948.0 1948.2 1948.4 1948.6 1948.8606 - 610 1949.0 1949.2 1949.4 1949.6 1949.8
611 - 615 1950.0 1950.2 1950.4 1950.6 1950.8616 - 620 1951.0 1951.2 1951.4 1951.6 1951.8621 - 625 1952.0 1952.2 1952.4 1952.6 1952.8626 - 630 1953.0 1953.2 1953.4 1953.6 1953.8631 - 635 1954.0 1954.2 1954.4 1954.6 1954.8
636 - 640 1955.0 1955.2 1955.4 1955.6 1955.8641 - 645 1956.0 1956.2 1956.4 1956.6 1956.8646 - 650 1957.0 1957.2 1957.4 1957.6 1957.8651 - 655 1958.0 1958.2 1958.4 1958.6 1958.8656 - 660 1959.0 1959.2 1959.4 1959.6 1959.8
661 - 665 1960.0 1960.2 1960.4 1960.6 1960.8666 - 670 1961.0 1961.2 1961.4 1961.6 1961.8671 - 675 1962.0 1962.2 1962.4 1962.6 1962.8676 - 680 1963.0 1963.2 1963.4 1963.6 1963.8681 - 685 1964.0 1964.2 1964.4 1964.6 1964.8
686 - 690 1965.0 1965.2 1965.4 1965.6 1965.8691 - 695 1966.0 1966.2 1966.4 1966.6 1966.8696 - 700 1967.0 1967.2 1967.4 1967.6 1967.8701 - 705 1968.0 1968.2 1968.4 1968.6 1968.8706 - 710 1969.0 1969.2 1969.4 1969.6 1969.8
PCS 1900 CHART 2 -- DOWNLINK (Base Station To Mobile)(continued)
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Useful Data - GSM P-8
CHANNEL NUMBERS
DOWNLINK FREQUENCIES(MHz)
711 - 715 1970.0 1970.2 1970.4 1970.6 1970.8
716 - 720 1971.0 1971.2 1971.4 1971.6 1971.8
721 - 725 1972.0 1972.2 1972.4 1972.6 1972.8
726 - 730 1973.0 1973.2 1973.4 1973.6 1973.8731 - 735 1974.0 1974.2 1974.4 1974.6 1974.8
736 - 740 1975.0 1975.2 1975.4 1975.6 1975.8
741 - 745 1976.0 1976.2 1976.4 1976.6 1976.8
746 - 750 1977.0 1977.2 1977.4 1977.6 1977.8
751 - 755 1978.0 1978.2 1978.4 1978.6 1978.8
756 - 760 1979.0 1979.2 1979.4 1979.6 1979.8
761 - 765 1980.0 1980.2 1980.4 1980.6 1980.8
766 - 770 1981.0 1981.2 1981.4 1981.6 1981.8
771 - 775 1982.0 1982.2 1982.4 1982.6 1982.8
776 - 780 1983.0 1983.2 1983.4 1983.6 1983.8
781 - 785 1984.0 1984.2 1984.4 1984.6 1984.8
786 - 790 1985.0 1985.2 1985.4 1985.6 1985.8
791 - 795 1986.0 1986.2 1986.4 1986.6 1986.8
796 - 800 1987.0 1987.2 1987.4 1987.6 1987.8
801 - 805 1988.0 1988.2 1988.4 1988.6 1988.8
806 - 810 1989.0 1989.2 1989.4 1989.6 1989.8
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Useful Data - GSM P-9
PCS 1900 CHART 3 -- UPLINK (Mobile to Base Station)
CHANNEL NUMBERS
UPLINK FREQUENCIES(MHz)
512 - 515 1850.2 1850.4 1850.6 1850.8516 - 520 1851.0 1851.2 1851.4 1851.6 1851.8521 - 525 1852.0 1852.2 1852.4 1852.6 1852.8526 - 530 1853.0 1853.2 1853.4 1853.6 1853.8531 - 535 1854.0 1854.2 1854.4 1854.6 1854.8
536 - 540 1855.0 1855.2 1855.4 1855.6 1855.8541 - 545 1856.0 1856.2 1856.4 1856.6 1856.8546 - 550 1857.0 1857.2 1857.4 1857.6 1857.8551 - 555 1858.0 1858.2 1858.4 1858.6 1858.8556 - 560 1859.0 1859.2 1859.4 1859.6 1859.8
561 - 565 1860.0 1860.2 1860.4 1860.6 1860.8566 - 570 1861.0 1861.2 1861.4 1861.6 1861.8571 - 575 1862.0 1862.2 1862.4 1862.6 1862.8576 - 580 1863.0 1863.2 1863.4 1863.6 1863.8581 - 585 1864.0 1864.2 1864.4 1864.6 1864.8
586 - 590 1865.0 1865.2 1865.4 1865.6 1865.8591 - 595 1866.0 1866.2 1866.4 1866.6 1866.8596 - 600 1867.0 1867.2 1867.4 1867.6 1867.8601 - 605 1868.0 1868.2 1868.4 1868.6 1868.8606 - 610 1869.0 1869.2 1869.4 1869.6 1869.8
611 - 615 1870.0 1870.2 1870.4 1870.6 1870.8616 - 620 1871.0 1871.2 1871.4 1871.6 1871.8621 - 625 1872.0 1872.2 1872.4 1872.6 1872.8626 - 630 1873.0 1873.2 1873.4 1873.6 1873.8631 - 635 1874.0 1874.2 1874.4 1874.6 1874.8
636 - 640 1875.0 1875.2 1875.4 1875.6 1875.8641 - 645 1876.0 1876.2 1876.4 1876.6 1876.8646 - 650 1877.0 1877.2 1877.4 1877.6 1877.8651 - 655 1878.0 1878.2 1878.4 1878.6 1878.8656 - 660 1879.0 1879.2 1879.4 1879.6 1879.8
661 - 665 1880.0 1880.2 1880.4 1880.6 1880.8666 - 670 1881.0 1881.2 1881.4 1881.6 1881.8671 - 675 1882.0 1882.2 1882.4 1882.6 1882.8676 - 680 1883.0 1883.2 1883.4 1883.6 1883.8681 - 685 1884.0 1884.2 1884.4 1884.6 1884.8
686 - 690 1885.0 1885.2 1885.4 1885.6 1885.8691 - 695 1886.0 1886.2 1886.4 1886.6 1886.8696 - 700 1887.0 1887.2 1887.4 1887.6 1887.8701 - 705 1888.0 1888.2 1888.4 1888.6 1888.8706 - 710 1889.0 1889.2 1889.4 1889.6 1889.8
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Useful Data - GSM P-10
PCS 1900 CHART 4 -- UPLINK (Mobile to Base Station)(Continued)
CHANNEL NUMBERS
UPLINK FREQUENCIES(MHz)
711 - 715 1890.0 1890.2 1890.4 1890.6 1890.8
716 - 720 1891.0 1891.2 1891.4 1891.6 1891.8721 - 725 1892.0 1892.2 1892.4 1892.6 1892.8726 - 730 1893.0 1893.2 1893.4 1893.6 1893.8731 - 735 1894.0 1894.2 1894.4 1894.6 1894.8
736 - 740 1895.0 1895.2 1895.4 1895.6 1895.8741 - 745 1896.0 1896.2 1896.4 1896.6 1896.8746 - 750 1897.0 1897.2 1897.4 1897.6 1897.8751 - 755 1898.0 1898.2 1898.4 1898.6 1898.8756 - 760 1899.0 1899.2 1899.4 1899.6 1899.8
761 - 765 1900.0 1900.2 1900.4 1900.6 1900.8
766 - 770 1901.0 1901.2 1901.4 1901.6 1901.8771 - 775 1902.0 1902.2 1902.4 1902.6 1902.8776 - 780 1903.0 1903.2 1903.4 1903.6 1903.8781 - 785 1904.0 1904.2 1904.4 1904.6 1904.8
786 - 790 1905.0 1905.2 1905.4 1905.6 1905.8791 - 795 1906.0 1906.2 1906.4 1906.6 1906.8796 - 800 1907.0 1907.2 1907.4 1907.6 1907.8801 - 805 1908.0 1908.2 1908.4 1908.6 1908.8806 - 810 1909.0 1909.2 1909.4 1909.6 1909.8
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Useful Data - GSM P-11
MS/BTS POWER CHARTS
MOBILE POWER CLASSES
GSM 900 DCS 1800 PCS 1900
POWER
CLASS
MAXIMUM PEAK
POWER
dBmMAXIMUM
PEAKPOWER
dBm MAXIMUM
PEAKPOWER
dBm
1 20 W +43 1 W +30 1 W +30
2 8 W +39 0.25 W +24 0.25 W +24
3 5 W +37 --- --- 2 W +33
4 2 W +33 --- --- --- ---
5 0.8 W +29 --- --- --- ---
MOBILE POWER CONTROL LEVELS
POWERCONTROL
LEVEL
GSM 900
PEAK POWERdBm
DCS 1800
PEAK POWERdBm
PCS 1900
PEAK POWERdBm
0 +43 +30 +30
1 +41 +28 +28
2 +39 +26 +26
3 +37 +24 +24
4 +35 +22 +22
5 +33 +20 +206 +31 +18 +18
7 +29 +16 +16
8 +27 +14 +14
9 +25 +12 +12
10 +23 +10 +10
11 +21 +8 +8
12 +19 +6 +6
13 +17 +4 +4
14 +15 +2 +2
15 +13 0 016 reserved
17 reserved
18 reserved
19 reserved
20 reserved
21 reserved
22 to 29 reserved
30 +33
31 +32
BTS POWER CLASSES
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Useful Data - GSM P-12
BTSPOWER
CLASSGSM
MAXIMUM PEAKPOWER
dBm
1 320 -640 W +55 - 58
2 160 - 320 W +52 - 55
3 80 - 160 W +49 - 524 40 - 80 W +46 - 49
5 20 - 40 W +43 - 46
6 10 - 20 W +40 - 43
7 5 - 10 W +37 - 40
8 2.5 - 5 W +34 - 37
Micro BTS
GSM
M1 ?? - 0.25 W +19 - 24
M2 0.025 - ?? W +14 - 19
M3 ?? - 0.025 W +9 - 14
BTS
POWERCLASSDCS 1800
MAXIMUM PEAK
POWER
dBm
1 20 -40 W +43 - 46
2 10 - 20 W +40 - 43
3 5 - 10 W +37 - 40
4 2.5 - 5 W +34 - 37
Micro BTSDCS 1800
M1 0.5 - 1.6 W +27 - 32
M2 0.16 - 0.5 W +22 - 27
M3 0.05 - 0.16 W +17 - 22
BTSPOWER
CLASSPCS 1900
MAXIMUM PEAKPOWER
dBm
1 20 -40 W +43 - 462 10 - 20 W +40 - 43
3 5 - 10 W +37 - 40
4 2.5 - 5 W +34 - 37
Micro BTSPCS 1900
M1 0.5 - 1.6 W +27 - 32
M2 0.16 - 0.5 W +22 - 27
M3 0.05 - 0.16 W +17 - 22
Reference Sensitivity Levels
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Useful Data - GSM P-13
MS Reference sensititvity dBm
GSM mobile class 1, 2, 3 -104
GSM handportable class 4 & 5 -102
DCS 1800 class 1 & 2 -100
DCS 1800 class 3 -102
PCS 1900 all classes -102
BTS Reference sensititvity dBm
GSM standard BTS -104
GSM Mini 1 -97
GSM Mini 2 -92
GSM Mini 3 -87
DCS 1800 standard BTS -104
DCS 1800 Mini 1 -102
DCS 1800 Mini 2 -97
DCS 1800 Mini 3 -92
PCS 1900 standard BTS -104
PCS 1900 Mini 1 -102
PCS 1900 Mini 2 -97
PCS 1900 Mini 3 -92
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Useful Data - GSM P-14
CONVERSION FACTORS
To convert between dBV (emf), dBV/m and dBm, use the following formulae:
dBV(emf) = dBm + 113.0
dBV/m = dBm + 136.5
Note: This assumes 0 dBi antenna gain and a frequency of 925 MHzRef. GSM Rec. 05.05 Section 5.
Some useful values are given below:
dBm dBV
(emf)
dBV/m
-110.0 3.0 26.5
-104.0 9.0 32.5-102.0 11.0 34.5-101.0 12.0 35.5-99.0 14.0 37.5-93.0 20.0 43.5-85.0 28.0 51.5-64.5 48.5 72.0-48.0 65.0 88.5-43.0 70.0 93.5
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Rx_QUAL Values
The reported Rx_QUAL values for received signal level are as follows:
Rx_QUALValue
Bit Error RateRange
Mean Value
0 < 0.2 % 0.14 %1 0.2 - 0.4 % 0. 28 %2 0.4 - 0.8 % 0.57 %3 0.8 - 1.6 % 1.13 %4 1.6 - 3.2 % 2.26 %5 3.2 - 6.4 % 4.53 %6 6.4 - 12 8 % 9.05 %7 > 12.8 % 18.10 %