LTE Planning

LTE Planning Prepared By: RF Team

AbdelRahman Fady & Mohamed Mohsen

LTE Planning Procedures

• Planning process is a very vital process we should do it carefully to get good network performance

• LTE Planning Process consists of three main steps as below

• Preplanning • Information Gathering • Dimensioning

• Detailed planning • Prediction & Simulation • TSS • Code Planning • Neighbors Planning • Parameters planning

• Acceptance • SSV • KPIs

Information gathering • Dimensioning Procedures should follow information gathering job about the nature of the

subscriber and the area • We can divide the gathered information into the following

• Design Information • Required BLER • Minimum RSRP • Limited MCS • ……. etc.

• Inventory information • Number of GSM/UMTS sites • Type of antennas • MIMO existence • TMA existence • …. etc.

• RF features • Scheduler type • …… etc.

• Subscriber information • Mixed services Traffic Model • Users behaviors • ….etc.

• Coverage information • Clutter type • ….etc.

LTE Dimensioning Concept

Dimensioning Procedures should follow information gathering job about the nature of the subscriber and the area

Dimensioning could be divided into two main steps as following

• Capacity dimensioning • Coverage dimensioning

Both capacity and coverage dimensioning process should be balanced

Coverage Dimensioning

Capacity Dimensioning

Gathered Info.

• Cell radius (R) • Inter site distance (I) • Number of sites (N) • Main design info


Dimensioning Procedures should follow information gathering job about the nature of the subscriber and the area

Dimensioning could be divided into two main steps as following

• Capacity dimensioning • Coverage dimensioning

Both capacity and coverage dimensioning process should be balanced

N = Total Area / Site Area (A)

A = 1.94 * R^2 … directional antenna or

A = 2.5 * R^2 … omni antenna

D = 1.5 * R




Modify

Get ( R )

Get ( N & D )

Coverage dimensioning

• Coverage Dimensioning Steps


Uplink Link budget

Downlink Link Budget

Get (MAPL) Limited one

Get ( R ) , Get ( D ) and Get ( N)

Subs. In Propagation Model equation



• Uplink Coverage : considering the uplink is the limitation we will start with it.

• Bit rate requirement

• SINR requirement

a0, a1, a2 and a3 are fitted parameters and the SINR is expressed in dB. The semi-empirical parameter a0 represents the maximum obtainable bit rate in one resource block.



• Uplink Coverage • SINR requirement

DL Fitted parameters

UL Fitted parameters



• Uplink Coverage • Bit rate requirement


• eNodeB Receiver sensitivity






• Noise rise calculation






• Noise rise calculation

• UE power per RB



• Uplink Link Budget MAPL_Uplink = Pue,rb – eNB_senstivity – penetration loss – body loss – FFM – Noise_rise - LNF_margine – AS_losses + Ant_gain + another Gains

Log Normal fading




Building penetration Losses




• Car_losses is typically 7 to 8 dB

• Fast Fading margine is typically from 0 to 2 dB

• Body Loss is typically 0 to 5 dB

• AS_losses = Feeder_Loss + Jumber_Loss + connector_losses

• Ant_Gain is typically 18 dB

• Another system gain like MIMO gain or TMA gain



• Downlink Link Budget MAPL_Downlink = P_RB – LTE-Ue_senstivity – penetration_loss – Car_Losses – IM - body loss – FFM – LNF_margine – AS_losses + Ant_gain + another system Gains

• P_RB = HPA_Power / Nrb

• Nrb is the number of RB per carrier as explained before

• LTE-Ue_senstivity = Nt + Nf + 10 log (Nrb” * 180KHZ) + SINR

• Nrb” is number of RBs assigned for single subscriber @

cell edge. It should depend on the required throughput at

cell edge.




• How to get SINR_DL….?




• How to get SINR_DL….?




• Interference Margin

• Due to using RP = 1 in LTE

@ cell edge we have to

expect level of interference

this level of interference

should be varies with cell

load hence we have to

consider this level of

interference during our

calculations of MAPL




Log Normal fading




Building penetration Losses




• Car_losses is typically 7 to 8 dB

• Fast Fading margine is typically from 0 to 2 dB

• Body Loss is typically 0 to 5 dB

• AS_losses = Feeder_Loss + Jumber_Loss + connector_losses

+ TMA insertion Loss

• Ant_Gain is typically 18 dB

• Another system gain like MIMO gain or Scheduler gain


• Get limited MAPL then substitute in propagation model equation to get R

• Radius calculation ( R )


• Target of capacity dimensioning is to get the number of cells / sites we do need to accommodate the offered traffic.

N = Total Number of users / Number of users per site (Nuser) Nuser = No# cells / site * Number of users per cell (Ncell) Ncell = Traffic per cell / traffic per user


Get ( N )


• Target of capacity dimensioning is to get the number of cells / sites we do need to accommodate the offered traffic.


Uplink Number of sites

Downlink Number of Sites

Get (N) Limited one

Balance to Get final ( R, D & N)

Back with New (N) to Coverage


• Cell Capacity Calculation • Cell Capacity calculation

• TCell = Tmax * Q • Where

• Tmax is the maximum cell throughput • Q is the maximum cell loading factor

• Tmax = (((Number of bits / symbol) * 144)/ 1 msec ) * Nrb * MIMO_order * (1-

CCH_ratio)

• Where • Number of bits / symbol = Modulation order * Code rate • Nrb is the total number of resource block per carrier • CCH_ratio is the ratio of control channels • MIMO_order is the degree of MIMO


• Cell Capacity Calculation • User capacity calculation

BLERRatioDutySessionTimeSessionbearRatekbitsfficSessionTra

1

1)(

] )*[()(/ ii nRatePenetratiofficSessionTraBHSAkbpsuserroughputBusyHourTh

Bearer Rate: Required Rate for the service

Session Time: PPP Session Time

Session Duty Ration: what is the percentage of active

transmission per session

BLER: Block Error Rate

BHSA: Busy Hour Session Attempts

Penetration Rate: percentage of service user


Traffic Modeling

Mean Bit Rate (Kbps) PPP Session

Time (s)

PPP Session

Duty Ratio BLER

Throughput Per

Session (Kbit)

UL DL UL DL UL DL UL DL UL DL

VoIP 32 32 210 210 0.4 0.4 1% 1% 2715.15 2715.15

Video Phone 64 64 54 54 1 1 1% 1% 3490.91 3490.91

Video

conference 128 192 1800 1800 1 1 1% 1% 232727 349091

Interactive

Gaming 50 64 1800 1800 0.2 0.4 1% 1% 18181.8 46545.5

Streaming

Media 10 300 3600 3600 0.05 0.95 1% 1% 1818.18 1036364

Instant

Messaging 20 20 7 7 0.2 0.2 1% 1% 28.2828 28.2828

Web Browsing 8 256 1800 1800 0.05 0.05 1% 1% 727.273 23272.7

Email 256 256 300 300 1 1 1% 1% 77575.8 77575.8

Thank You

Date post:	16-Jul-2015
Category:	Documents
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LTE Planning

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