Evolution in mobile technology can be traced as far back as the late 70’s and early 80’s characterised by the development of the first generation (1G) technologies that were purely analogue in performance. >From around the late 80’s, second generation (2G) technologies were developed and the success of 2G systems opened up many opportunities for the development of additional applications i.e. data services.
The technology evolution path has seen the transition of services from 1G through 2G to the present 3G on the way to 4G. The earlier technologies were purely designed to primarily handle voice services, but modern day systems have incorporated the provision of data services and the LTE-Advanced system is the first cellular technology standard to be fully optimised for data services, a key step in the mobile telecommunications industry.
Successful implementation of 3G technologies was a result of joint efforts by many sectors outside and within ITU spanning a research period of 10 years. In October 2010, ITU finally accepted LTE-Advanced system (Release 10 & beyond) and WirelessMAN-Advanced system (Wi-Max 802.16m) as two designated 4G technology standards under the common classification of IMT-Advanced system.
ThreeG technologies focused on the multimedia aspect of service delivery while 4G technologies are primarily user-centred allowing the user centre stage in deciding and utilising the services. The LTE-Advanced system has been developed on the premise of fully packetswitched services making use of the evolution for non-radio aspects and will implement a fully-fledged all IP network configuration offering considerably high level performances across many parameters. In a fast changing technology environment from radio transmission to applications, LTE-Advanced system is expected to adapt reactively or proactively either automatically or through user requests. The system design has significantly improved and enhanced most of the features that were characteristic of its prede-cessor technologies.
LTE-Advanced system has been developed to offer reliable voice, video and data services with peak rates of at least 100 Mbp/s downlink and 50 Mbps uplink which is about four times the peak values offered by its predecessor technologies. To counter the effects of signal loss for varying distances of the receiver terminals from the base station, the system makes use of the multi-antenna techniques so that performance levels are not compromised for average transmission data rates. Typical multi-antenna patterns will make use of the 2:1 ratio between receive and transmit antennas. Depending on the frequency band used, the system is designed to support vehicular motion for mobile terminals at speeds in the range of 350 – 500 Km/h over wide deployment areas. Utilising a defined common air-interface, the system can therefore support more services with better quality than 3G systems.
System interoperability with prevailing technologies is a key component in any transition process. Unlike WirelessMAN-Advanced system (fixed/mobile) that might require new network infrastructure roll-out, LTE-Advanced system will easily ride on the various 3G access networks requiring only upgrading to handle the integrated advanced system design. While it can still be argued that both systems are data and IP-based, LTE-Advanced system offers seamless transition options for all standards, thus reducing the cost of transition.
LTE-Advanced system is greatly premised on the success principles of the earlier standards to develop a user-centred concept offering relatively low cost terminal equipment with prolonged active life. Backward compatibility with previous technologies offers the user a wide range of terminals from low cost to high capability terminals that support end to end services. For the high end services, the user terminals are equipped with intelligence to select the best channel options available thus facilitating good quality of service between the terminal and the network over the radio channel. The system is also designed with the capability to integrate other services as part of service convergence i.e. mobile television services.
Read Part 2 on Friday-May 4.
—The author is a Telecommunications Engineer working with Macra, writing in his personal capacity.
