GSM Architecture https://www.youtube.com/watch?v=6qR102lcXoYGSM serviceshttps://www.youtube.com/watch?v=WvrU3TJ9K8shttps://www.youtube.com/watch?v=xGZsCL_J1cgSMS Workinghttps://www.youtube.com/watch?v=izxcOK9u5mgMULTIPLE ACCESS - FDMA/TDMA/CDMA/OFDMA

https://www.youtube.com/watch?v=oYRMYSIVj1oHow the cellular network works? - GSM Architecture

https://www.youtube.com/watch?v=iS8jmhVAfoQ

The Process Behind Sending An SMS Message Using A 2G GSM Network

https://www.youtube.com/watch?v=izxcOK9u5mg

How does your mobile phone work? 

https://www.youtube.com/watch?v=1JZG9x_VOwA

Note:The above links are easier for understanding the architecture, services and working very easily. First you see the videos and then go to study the PPTs. If you want to add more points use these videos.

How roaming services is carried out in cellular network?

International mobile roaming is a service that allows mobile users to continue to use their mobile phone or other mobile device to make and receive voice calls and text messages, browse the internet, and send and receive emails, while visiting another country. Roaming extends the coverage of the home operator’s retail voice and SMS services, allowing the mobile user to continue using their home operator phone number and data services within another country. The seamless extension of coverage is enabled by a wholesale roaming agreement between a mobile user’s home operator and the visited mobile operator network. The roaming agreement addresses the technical and commercial components required to enable the service.The most common international roaming services are:

Voice: Making and receiving calls to or from home country, visited country or a third country, while abroad

SMS: Sending and receiving text messages to or from home country, visited country or a third country, while abroad

Email: Reading and replying to emails while abroad Mobile broadband: Using mobile devices or dongles to access the internet,

including downloading images, MP3s, films and software, while abroad Applications: Using mobile applications while abroad that require mobile

data, such as location-based services and language translators.How mobile roaming works When a mobile user is abroad and turns their mobile device on, the mobile device attempts to communicate with a visited mobile network. The visited network picks up the connection from the user’s mobile, recognises whether it is registered with its system, and attempts to identify the user’s home network. If there is a roaming agreement between the home network and one of the mobile networks in the visited country, the call is routed by the visited network towards an international transit network (Figure 1.1). The international transit network carrier is responsible for the call delivery to the destination network. Once this is done, the destination network will connect the call. The visited network also requests service information from the home network about the user, such as whether the phone being used is lost or stolen, and whether the mobile device is authorised for international use. If the phone is authorised for use, the visited network creates a temporary subscriber record for the device and the home network updates its subscriber record on where the device is located so if a call is made to the phone it can be appropriately routed.

To explain roaming in more detail, Figure 1.2 the shows commercial and technical details for international mobile roaming. The diagram focuses on the international roaming wholesale and retail arrangements, for simplicity. The mobile user (Mobile User A) has an international roaming service with their home operator (Home Operator) and is automatically connected to a visited network (Visited Operator A) while roaming. Mobile User A is automatically granted access to Visited Operator A’s network when arriving in the visited country by an exchange of a data between Home Operator and Visited Operator A, where Visited Operator A confirms Mobile User A is a roaming customer with Home Operator. As such, the wholesale roaming agreement between Visited Operator A and Home Operator specifies how this data is to be provided to the visited operator. Home Operator usually has wholesale roaming agreements with more than one operator in the same visited country, which in this case is Visited Operator A and a second network, Visited Operator B. As a result, Mobile User A can call home using either visited operator networks, both of which use international transit services to carry the call back to Mobile User A’s home country. Mobile User A pays a retail price to Home Operator for the roaming service and does not pay Visited Operator A. Provided Mobile User B is not also roaming, they will not incur any extra charges to receive a call from, or to make calls to Mobile User A. Visited Operator A sends transferred account procedure (TAP) files to a clearing house which forwards them to the Home Operator. TAP files are used for billing of calls while roaming. Home Operator can then pay Visited Operator A the wholesale charges as per call volumes in the TAP file and rates in the wholesale roaming agreement. Visited Operator A pays an international carrier (International Carrier) for carrying the call and handing over the call to Home Operator. International Carrier pays Home Operator a termination rate for terminating the call in the home country.

Roaming service

Roaming service is the ability to get access to the Internet when away from home at the price of a local call or at a charge considerably less than the regular long-distance charges. For example, if you normally get access to the Internet from an access provider in Brooklyn, New York and are travelling to Hong Kong, you can call a designated access provider in Hong Kong. Instead of paying long distance charges to your local provider in Brooklyn, you pay the local phone connection charge in Hong Kong and possibly a modest additional charge for the service.

Roaming service is made possible through Internet service providers (ISPs) who have cooperative agreements to grant each others' customers local access to the Internet. Special software allows cooperating ISPs to keep track of and calculate prearranged payments for usage differences. Here's how it works for the user:

1. The Internet user must already subscribe to an ISP that offers roaming service arrangements.

2. Assuming the ISP does, the user can determine a cooperating ISP in a city to which the user is travelling.

3. In the travel location, the user can call the local ISP's designated phone number through the computer modem, entering information during login that will identify the user's home ISP.

4. The "foreign" ISP will contact the ISP and determine that the user is a valid user.

5. The "foreign" ISP will grant the user access to the Internet. The user will be able to access e-mail from the home mail server.

6. The user will be charged at local phone rates. In addition, depending on the particular service arrangement, the home ISP may levy an additional hourly usage charge of several dollars an hour or a monthly charge in case the service is used during that month.

A similar roaming service is provided by some cooperating cellular telephone telephone or personal digital assistant (PDA) service providers.

If you are travelling and simply need to be able to exchange e-mail, you can consider getting a freemail membership (usually free) from HotMail, Rocketmail, or other freemail providers. Hotmail also offers POP3 server accounts for access to up to four e-mail accounts you may already have, assuming you remember the POP3 server name and your user IDs and passwords.

List the features of LTE:

Significantly increased peak data rates e.g. 100 Mbps in downlink/50 Mbps in uplink

Increased bitrates at the edge of cells assuming current site locations Improved spectrum efficiency e.g. 2-4 x Rel-6 Reduced latency Scaleable bandwidth for a greater flexibility in frequency allocations Reduced capital and operational expenditure including backhaul Acceptable system and terminal complexity, cost and power consumption Support for inter-working with existing 3G systems and non-3GPP specified

systems Efficient support of the various types of services, especially from the PS

domain (e.g. Voice over IP, Presence) Optimized for low mobile speed but supporting high mobile speed (up to 500

km/h).

LTE was laucnched in 2004 Long Term Evolution (LTE) 

LTE was the 4G successor to the 3G UMTS system which was developed to provide a further evolution of the mobile telecommunications system available.

Providing much higher data speeds and greatly improved performance as well as lower operating costs, the scheme started to be deployed in its basic form around 2008.

What is VoLTE?

VoLTE stands for voice over Long Term Evolution. Utilising IMS technology, it is a

digital packet voice service that is delivered over IP via an LTE access network.

VoLTE stands for voice over LTE and it’s more or less exactly what it says on the tin. It's voice calls over a 4G LTE network, rather than the 2G or 3G connections which are usually used.

What are the benefits of VoLTE?

Superior call quality

The big advantage of VoLTE is that call quality is superior to 3G or 2G connections, as far more data can be transferred over 4G than 2G or 3G. Up to three times as much data as 3G and up to six times as much as 2G to be precise, making it easier to make out not only what the person on the other end of the line is saying, but also their tone of voice.Essentially it’s an HD voice call and it’s a much richer experience overall.

Improved coverage and connectivity

VoLTE can connect calls up to twice as fast as the current methods, and as 2G and 3G connections will still be available when there’s no 4G signal it simply means that there’s greater mobile coverage overall, as without VoLTE you wouldn’t be able to make or receive calls in places with a 4G signal but no 2G or 3G.

You might think that would be a rare occurrence, but some of the frequencies that 4G operates on, such as the 800MHz spectrum, have far greater reach than 2G or 3G spectrum, so you’ll be able to get signal further away from a mast or in buildings which other signals struggle to penetrate. Indeed, Three is fully relying on its 800MHz spectrum for VoLTE calls.However, while 2G and 3G services have largely remained so far they aren’t as necessary as they used to be, and much of the spectrum used for 2G in particular could potentially be repurposed to increase capacity on 4G or 5G networks.

Better battery life

Smartphone users could also find their battery life increased with VoLTE, as without it whenever you make or receive a call your phone has to switch from 4G to 2G or 3G, since 4G calls aren’t supported, and then once the call is finished your phone switches back again. All that switching, plus the need to search for a different signal each time, can give the battery a significant hit.

Faster data

As you don’t have to switch to 3G when making a call with VoLTE, that means you can also keep using 4G for other functions on your phone while on a call. That’s handy if you’re multi-tasking. For example, browsing the web at the same time or downloading an app.

Works with Wi-Fi

4G Calling also offers the ability to seamlessly move between that and Wi-Fi Calling, without the call cutting out, so if you move away from one signal type you can continue on the other.

Video calling 

It’s also theoretically possible to make video calls over 4G, much like a Skype call, except you’d just use your mobile number and be able to use the regular dialler and call interface, so you can make and receive video calls from anyone else with VoLTE, rather than relying on separate accounts.

What are the benefits of VoLTE?The implementation of VoLTE offers many benefits, both in terms

of cost and operation. VoLTE:

Provides more efficient use of spectrum than traditional voice;is

Meets the rising demand for richer, more reliable services;

Eliminates the need to have Voice on one network and data on

another;

Unlocks new revenue potential, utilising IMS as the common

service platform;

Can be deployed in parallel with video calls over LTE and RCS

multimedia services, including video share, multimedia

messaging, chat and file transfer;

Ensures that video services are fully interoperable across the

operator community, just as voice services are, as demand for

video calls grows;

Increases handset battery life by 40 per cent (compared with

VoIP);

Delivers an unusually clear calling experience; and

Provides rapid call establishment time.

What is 5G?A: 5G is the 5th generation mobile network. It is a new global wireless standard after 1G, 2G, 3G, and 4G networks. 5G enables a new kind of network that is designed to connect virtually everyone and everything together including machines, objects, and devices.

5G wireless technology is meant to deliver higher multi-Gbps peak data speeds, ultra low latency, more reliability, massive network capacity, increased availability, and a more uniform user experience to more users. Higher performance and improved efficiency empower new user experiences and connects new industries.

5G is based on OFDM (Orthogonal frequency-division multiplexing), a method of modulating a digital signal across several different channels to reduce interference. 5G uses 5G NR air interface alongside OFDM principles. 5G also uses wider bandwidth technologies such as sub-6 GHz and mmWave.

What are the differences between the previous generations of mobile networks and 5G?The previous generations of mobile networks are 1G, 2G, 3G, and 4G.

First generation - 1G1980s: 1G delivered analog voice.

Second generation - 2GEarly 1990s: 2G introduced digital voice (e.g. CDMA- Code Division Multiple Access).

Third generation - 3GEarly 2000s: 3G brought mobile data (e.g. CDMA2000).

Fourth generation - 4G LTE2010s: 4G LTE ushered in the era of mobile broadband.

1G, 2G, 3G, and 4G all led to 5G, which is designed to provide more connectivity than was ever available before.

5G is a unified, more capable air interface. It has been designed with an extended capacity to enable next-generation user experiences, empower new deployment models and deliver new services.

How is 5G better than 4G?There are several reasons that 5G will be better than 4G: • 5G is significantly faster than 4G• 5G has more capacity than 4G• 5G has significantly lower latency than 4G• 5G is a unified platform that is more capable than 4G• 5G uses spectrum better than 4G