 The overall emphasis of the 3GPP community was to increase data rate so that better voiceover IP and other multimedia services could be provisioned. But it had to be done in such a way that the overall mobile telephony largely remained available and the system actually improved in a comprehensive manner. So the standardization process is not unilateral but it is based on a widely based standardization activity. We would look at the emphasis of standardization areas and we'll see how different technologies and different standards blended into the LTE standardization process across the time. Starting off with the fundamental requirement for any data provider, the focus of standardization was to have high speed access and this meant a significant improvement in the radio access technology. Better modulation schemes, better codecs, more use and efficient use of wider and bigger spectrum. So some of these techniques actually proved to be very very useful in achieving significantly high data rates. The second area was the core services. The core network was circuit switched in 2G and 2.5G networks. But in 3G onwards into LTE, all service provisioning backend servers like controllers, the gateways, the databases such as the HLR, VLR, etc. All had to be enabled for IP and even their connections were supposed to be based on the IP routing framework. So this was another focus area that helped standardize and make it more easily integrable with the classical computer networks. And the last area is the provisioning of better user services. The user services which were otherwise limited and proprietary were thought to be offered as an overlay network in this LTE standardization process. What it means is that regardless of the underlying network for as long as standard interfaces could be provided, the services could be offered as application programming interfaces or APIs to users which have different gadgets, mobile phones and are coming through different service providers. An example is IP multimedia subsystem that connects users for various services like voice over IP, multimedia over IP, signaling, logging, CDRs, IPDRs, all these services. Now the users could be having totally disparate and diverse range of devices. But as long as IP multimedia subsystem as a functional entity is provided, then it offers services as an overlay. Looking at what the focus areas were, it's going to be interesting to look at how the data rate improved and some of the technologies that helped offer these increasing data rates. The first one is actually known as the generalized or general packet radio service. This was actually offered as an overlay by incorporating two additional nodes into the GSM network architecture, the serving gateway service node and the gateway service node. Now these two nodes specifically were meant to provide internet connectivity. Now these two nodes were the entry or exit point to the IP network. Incorporating such entities into the network meant now a GSM network was IP enabled that was using the same radio access network technology and the multiplexing scheme was also not changed much. It was still based on time division multiple access over frequency division multiple access. So this resulted in actually two core networks. The first network being a circuit switched network and the second network was now a packet switched network that was sitting in parallel to that service switched network. After GPRS it was thought to have better user data rates. So enhanced data rates for global evolution was proposed known as the edge services. Those of you who have been actively using internet over the course of technological evolution over the last decade might have experienced seeing G or GPRS on your mobile phones. E you might have seen as edge technology available on your mobile phone. In Pakistan it means that we actually have seen all these technologies with our very own eyes and have experienced these. So edge was meant to provide relatively better data rates. It incorporated new modulation scheme at the radio access networks such as the GMSK known as the Gaussian minimum shift keying. The initial two nodes the SGSN and the GGSN continued and there was a reason for that because these two nodes have now a slightly expanded role of carrying the user traffic as well as the control traffic. It means that whatever signaling has to happen. These two nodes have now an extended role to provide the signaling and once the bearer path is established to have the data connection between the endpoints. One IP enabled endpoint is now on the mobile side and the other one is on the internet side with edge performing better than GPRS. The effort continued to have more data rates. So WCDMA was put in place around the middle of the 2000 era. The 3G standardization had strongly established the standards and documentation for the circuit switch domain and the packet switch domain. Two technologies were incorporated on the core side since everything is IP enabled. So back in those days ATM was also a packet switch technology. In fact, it's known as a cell switching technology since it did not have such a wide deployment. So ATM literally lost this battle to IP and IP became the de facto and to be more exact the DGEOR standard for the core network. So coming back after edge WCDMA or wide band core division multiple access was an advancement again on the radio side. And it promised data rates up to megabits per second. Now core division multiple access not being the scope here is actually a technology that significantly improves the data rate because unlike frequency division multiple access and time division multiple access, which have to share either the frequency spectrum or the time slices. The WCDMA is based on coding having orthogonal codes means that theoretically speaking an innumerable number of users can be accommodated. So the carrier bandwidth for 3G for WCDMA was extended from 200 kHz as in 2G to 5 MHz for WCDMA it meant an increase of over 25 times.