Generation x

With the race toward implementing wireless networks beyond 3G in full flow, the challenge to address existing limitations is being looked at in a number of ways. Demands for wireless services cross every sector and an emerging mobile society punctuates any inadequacies there may be. Long term evolution (lte) is an entirely new radio platform technology with standards currently under development by the third generation partnership program (3GPP) and initial deployment planned this year. LTE promises significant performance improvements for mobile data services, along with cost efficiencies for network operators. It is viewed by many as the gsm evolutionary path beyond 3G. Andrew Wireless Solutions has already been offered a number of projects by operators and OEMs for the development of equipment for use in 4G networks – both lte and WiMax – being implemented or planned. Andrea Casini, Andrew’s vp sales and marketing, EMEA, highlighted the different needs for different countries. “In western Europe, for example, it is evident there is uneven demand. In countries where 3G is not yet implemented, operators seem to be happy to stay at that level or, at best, invest in early research and development programmes for 4G. However, other countries have an increased need for communications, so we are seeing a greater investment in trials.” LTE, Casini pointed out, offers the best option in terms of allowing data to be transferred at a very high speed with an optimum network where costs have been minimised. “It’s useable on a broad range of frequencies,” he added. “For example, central Europe’s main allocated frequency is 2.6GHz. So, even without the generalisation of a general network band, it has the flexibility to be used globally.” According to Casini, there has been a progressive shift from WiMax to lte across mobile operators of late. “Operators who don’t have 2G or 3G,” he explained, “were looking into WiMax as a connectivity solution. But the interest seems to have dropped, primarily because of the recession and the fact that OEMs are reducing their budgets.” Darren Tipton, Rohde & Schwarz’ UK product manager for spectrum analysers, agreed: “Because of the economic situation, networks operators will be spending less on upgrades. The need to switch from 3G to 4G also depends on how networks are being used. From the other side, it’s not just vendors that have the problem. Operators such as Nokia are relying on chipset manufacturers and then have to sell the products. If lte has to be put back, where will the investment come from? So the recession has a knock on effect throughout the whole supply chain.” However, lte has enough industry support to ensure it will become the next generation of communication, superseding platforms such as WiMax. “The problem with WiMax,” said Casini, “is that it is confined into fixed wireless applications. So we are seeing operators taking a different approach. Some want high speed data in their buildings; others are more interested into a more macro type product.” Tipton is also well aware of the limitations of WiMax. “The fact that Nokia has announced that it isn’t going to continue manufacturing WiMax gives you an indication of where it is at the moment,” he asserted. “Like Tetra, the European standard for trunked radio systems, it is intended primarily for users in the public security sphere, transport, utilities and operators of public trunked radio networks. While it will have applications, many may not be in the public domain – emergency services for example. Many operators are now committed to lte, as a natural global progression.” Casini concurred: “LTE is regulated and harmonised within 2G and 3G environments on the same network and the same platform. WiMax is a different beast. For us it makes no difference; our job is to make sure we carry rf signals from one place to another in the best transparent way and to find a compromise between price and performance.” Tipton agreed compatibility is a major selling point. “Where lte works well,” he commented, “is in an existing rf stack so operators can build on an existing network.” Rohde & Schwarz is fully behind lte and its scalable multistandard platforms support all major standards. The company has a number of products based on lte, such as its SMU200A vector signal generator which has integrated real time fading for 2x2 MIMO receiver tests. Andrew has also been approached by a growing number of operators busy conducting trials for the next generation of wireless access. Casini pointed out: “We are discussing models with these companies, based on our technologies, to adopt a new approach which will minimise costs for the infrastructure. LTE will help subscribers expand from this version.”