RTT Technology Topics - 1998

We help companies and organisations maximise returns from existing technology and engineering investment.

1998 Title Synopsis
December 3G Wireless local loop The failure of Ionica in the UK underlined the market reality that wireless local loop technology needs to move on from its present voice-centric focus to delivering a mix of voice and non-voice services at equivalent bit rates and bit error rates to wireline at an equivalent (or preferably lower) cost per user bit delivered.
November Connectivity devices Both W-CDMA and Cdma2000 have time division duplexed protocols as part of their 3G platforms and in most markets 20 MHz of non-paired frequency allocation from 1900 to 1920 MHz is available for TD-CDMA services (1910 to 1930 MHz in the US).There is an obvious future development path for DECT and PHS to converge and develop together to evolve towards these integrated 3G air interface standards
October WCDMA The evolutionary path of W-CDMA and CDMA 2000, how the traffic mix will be managed in terms of active rate adaption, error rate and latency control, and how TD-CDMA fits in to this overall picture.
September Cordless and cellular convergence Cellular air interfaces have been developed and optimized for duplexed spaced frequency allocations, digital cordless air interfaces have been developed and optimized for simplex frequency allocations using time division rather than frequency division duplexing.The advantage of simplex frequency working has traditionally been that the architecture of the phone can be made simpler and theoretically lower cost. The disadvantage for digital cordless systems used in simplex frequency allocations (also sometimes described as 'non-paired spectrum') is that the range of the phone (coverage and/or cell radius) is limited by the time space (guard band in the time domain) between the Rx and Tx time slots. A DECT or PHS phone, even if high powered, suffers unacceptable intersymbol interference in a wide area cell.
August GPRS design Many multi-band design solutions are moving towards using off set phase locked loop (modulated loop) design architectures. This is an elegant way of implementing dual band and tri-band requirements but is incompatible with GPRS implementation