The rise of Data usage in Mobile communications has taken a sharp increase in the past years. It is very much linked with two major catalysts:

1. The upgrade of the Mobile network to WCDMA and LTE.
2. The availability of affordable smart mobile phones in the market.

You may ask is that all? Well there are famous and helpful applications, as listed below which you are using:

1. Facebook
2. Twitter
3. You tube
4. Net Flix
5. Mobile Games

Let’s face it data has changed our lives significantly in the last 5 years. Facebook which captured social networking by storm has changed the way we use data and information. To find a lost connection whether family or friend from your home country to a foreign land is now possible. We use Facebook as a means of business promotion platform. Incubation of an idea, if it will catch the attention of your target market. It’s the same with Twitter, posting of hashtags and relevant events or questions. Want to watch your favorite video or listen to old songs? Just go to You tube and watch it. If you want to see great movies and new TV series, Net Flix has a lot to offer you. Want to play with your friends on-line? Your mobile phone can instantly hook you up on new mobile games and play virtually with your friends wherever they are in the globe. We all enjoy the new-found applications which runs on your mobile phone and gadgets. Powered by the data network of Telco operators here in the Philippines. You may wonder how this is possible. It is possible by the use of this mobile technology known as WCDMA. It is defined as Wide Band Code Division Multiple Access. This access technology is capable of voice and data throughput. Capacity is doubled for voice and data. This is a distinct advantage over TDMA technology for both voice and data capability.

Please find the figure below, which shows the system diagram of a 3G (WCDMA) network:

Diagram Source: www.techdifferences.com

I choose this diagram which shows the name and function of each equipment. Always remember that the link between the network and the subscriber is the mobile station or mobile equipment. This also gives the subscriber the user experience to tell if the network is performing well or not. We can see that this architecture is very similar to GSM, connections to circuit switch for voice services are the same with GSM. The big difference is the improved core network, which does not only have the SGSN but has the GGSN as well. The IMS portion will play a significant role once we talk about LTE networks later. This architecture has given our WCDMA or 3G network both voice and data capabilities beyond GSM networks. Please find the advantages of WCDMA:

1. Improved voice quality and capacity, this is due to the characteristics of the access technology itself.
2. It uses the same frequency (or carrier) in the whole network.
3. It does not have any hard hand overs compared to GSM. Hard handover are changes between different frequencies in the cellular network. In one carrier frequency, hand-overs are the transfer of one voice call or data service from one cell to another. In WCDMA it is called soft handovers since it is with the same frequency in the whole network.
4. It has more code identifiers (Scrambling Codes) compared to the use of BCCH channels in GSM.
5. This network gives more data throughput. For the Downlink it is 21Mbps and for Uplink it is 5Mbps. This makes downloading or uploading files or videos faster than GSM.

Let’s now look at the LTE architecture with this diagram:

Diagram Source: www.techdifferences.com

At a single glance you might wonder what happened to the controller in the E-Utran system. In GSM or WCDMA we have a BSC (Base Station Controller) and for WCDMA it is RNC (Radio Network Controller). Now for 4G the e-BS or e-Node B has included the controller function, which simplifies the E-Utran system. This makes the decision such as hand-overs from one cell to another faster. This also improves the data throughput faster response control wise. The main access control technology used in 4G is called OFDMA (Orthogonal Frequency Division Multiple Access). This is a single frequency network similar to WCDMA, the main difference is that it has better interference control. This applies to different cells, its ability to average the interference and use it to give more data throughput in the whole process. It also uses MIMO technology, which is combining multiple inputs and giving better throughput using diversity.

Going to the Evolved Packet Core we can see new equipment used, namely the MME. The HSS, S-GW, P-GW, PCRF their function has been improved. We would like to remind that in LTE is a pure data network. It does not have and circuit switch component like WCDMA. The circuit switch is used for Voice calls and services, this is used by WCDMA networks. In LTE since it is pure data, when you make a voice call the LTE network will transfer you to a WCDMA cell. This process is called CSFB (Circuit Switch Fall Back), as the term suggest the LTE network will transfer you to a live WCDMA cell and once your call is finished you go back to the LTE network. In LTE networks we will add a new equipment called the IMS (IP Multi Media System). This equipment would allow the LTE network to use Vo-IP (Voice over IP) calls. No need to transfer to a WCDMA cell to make a voice call. However, there are quality issues when using Vo-IP and pure Voice calls. You can experience this when you make a call using Viber or FB Messenger. Please note the quality of the voice call when using a GSM or WCDMA network. But still, Vo-IP will continue to improve as technology is upgraded to give subscribers the best voice quality. The advantage of LTE are as follows:

1. Data throughput is achieved up to 1Gbps for downlink.
2. Uplink is 500Mbps
3. Reduce delays in Transmission and Data Latency.
4. Handover is done both vertically and horizontally
5. The whole network is pure IP end to end. It does not have and Circuit switch component.

This LTE network also gives better cost efficiency due to its full IP Network architecture. We can see the improvement of cellular networks, towards data usage and driven by devices and applications in both mobile phones and PC. In our next blog we will talk about a technology which is popular in the data services. I think you are familiar already with the term Wi-Fi, but let me help simplify it for you. Most especially with the name Wi-Fi and its relationship with LAN. See you in the next blog.

Disclaimer: This Blog is the product of the authors 20 years’ experience in the Cellular Telecommunications in the Philippines. This does not have any relation or thoughts with my current, former and future employers. This includes my customers in all my years in Telecoms in the Philippines. All ideas are mine by way of experience. References are found in Wikipedia and corporate websites in the internet which are for public use and viewing. This includes presentations or Blog pages which are acknowledged by the author.