Testing Facing a mismatch
In delivering the next generation of wireless networks, says Paul Beaver, of Anite, testing will be essential to ensuring that the new devices live up to expectations
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ales of smart devices, tablets and other connected devices that provide access to mobile broadband and data services
continue to skyrocket. In a recent report, IMS Research forecasted that the number of smart- phone sales reached 420 million by the end of 2011, and that the fi gure would rise to a stagger- ing one billion devices by 2016. Moreover, Juni- per Research estimated that 55·2 million tablets were shipped in 2011 and that this fi gure would climb to 253 million by 2016. Exponential sales growth of smart devices is
good news for chipset and handset manufac- turers, and for mobile operators. But all these players face the challenge of ensuring that these devices generate the optimum level of data throughput that will allow the end-user to access applications and services.
Networks under stress An insatiable demand for wireless access to data has ensured rising smartphone and tablet sales. However, the proliferation of these devices places a signifi cant burden on mobile networks. T e applications supported by smart devices consume mobile bandwidth at a terrifi c rate. Web browsing, email and video streaming re- quire a signifi cant amount of data throughput; and even when these devices are idle they are still constantly connecting to the network to receive updates and notifi cations. Operators have responded to this situation by
starting to migrate to LTE networks to increase capacity and cater for the high demand for data services. Indeed, the Global Mobile Suppliers Association states there are 35 commercially launched LTE networks, and 185 commitments to launch from operators in 66 countries. LTE promises to deliver high-speed mobile broad- band, but the data rates it can provide will be
aff ected by a number of variables that manufac- turers and operators need to take into account.
Data rate dilemma T ere is also a need for alignment within the industry on how data throughput and peak data rates are communicated, such that the end-user’s experience lives up to expecta- tions. In plain terms, there is a mismatch be-
tween the standards-based peak data rates cited by the industry and actual network data rates. On smart devices, the com- monly quoted standards-based peak data rates are rarely achieved. Factors that can aff ect data rates
are variable signal quality, network bandwidth and resource allocation, the time of day and the number of concurrent users within a specifi c cell-site, among others. At application level, data rates are always lower than the physical layer rates described in specifi cations. T is means that even with perfect signal quality, the theoretical data rate at application level is lower than the peak data rates. T e gap is in the range 3–3·5 per cent.
Creating confi dence In order to accurately assess data throughput levels for LTE, and other mobile technologies, the industry will, of course, turn to device testing and measurement. T is method has traditionally provided manufacturers and operators with the means to optimize handsets and make sure they perform consistently and effi ciently in a network environment. T e precise specifi cs of the network envi-
ronment that devices are expected to perform in can be emulated in the laboratory. T is can help operators to qualify the highest-performing devices, giving them the confi dence to be more
Above: the OSI (Open Systems Interconnection) reference model, a scheme that defi nes the stages which data passes through when travelling from one device to another via a network
transparent with customers on what their net- work and portfolio devices can deliver in terms of data throughput.
A common understanding As LTE deployments continue to gain pace in global markets, the industry will need to use all the methods at its disposal to understand how all these new types of devices function, and actually perform, on next generation networks. Testing and measurement will play a crucial role in this process. But conducting this assessment of LTE de-
vices using a clear view on data throughput will help identify the genuine best of breed off erings to bring to market, while also allowing the in- dustry to provide clarity on their performance when accessing data and services.
About the author ‘The industry would benefi t from a wider adoption of laboratory-based test
Paul Beaver is products director for Anite Telecoms, which supplies test systems for mobile devices and networks
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and measurement techniques, which test devices in accordance with typical user profi les and network conditions’
LAND mobile January 2012
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