Although many view it as a post-3G technology that needs to wait its turn in a world that hasn’t got to grips with 3G yet, IP Wireless’ Chris Gilbert is adamant that TDD is already here, and is part of a growing “ecosystem”.
IP Wireless’ most recent expansion of that TDD ecosystem is to announce UTStarcom as a licensee for network infrastructure and devices.
Gilbert also pointed to networks in South Africa and New Zealand where TDD was “going gangbusters”. New Zealand broadband provider Whoosh Wireless is gaining 50% of all broadband subscriber additions where DSL is the rival technology, Gilbert claimed.
“From a technical point of view we are building different base stations and end user devices, the chipsets are now condensed on fourth generation ASICs. Modems that last year were running on 1.2Mbps are now running at 4.4Mbps.
“From a base station point of view because the radios are software based upgrades are at virtually zero cost and very fast.”
For the moment TDD services are data only, but Gilbert said some fixed line VoIP telephones could be utilised soon by service providers. It would be “at least a year” before any mobile phones were available, he said.
In terms of mobile operators themselves adopting TDD, Gilbert said the situation was “very frustrating.” “Operators like to keep very quiet. We will be seeing a network in Europe, and Asia is going bananas.
“There are two types [of TDD operator]. The new ‘non-mobile’ operators from the DSL market whose approach is very different, and the mobile operators who are looking at data as an adjunct.
“The two sides are going to clash.”
So far, IP Wireless’ main wins have been for service providers providing a fixed wireless-type service. In Stuttgart, Telefonica and Airdata are partnering to offer a wireless broadband service, at peak rates of 768kbps.
But Gilbert defends the technology from those who say implementations of it so far are not truly mobile.
“It is 100% mobile, operating at standard GSM handover speeds.”
The mobile breakthrough will come, Gilbert says, when one mobile operator in a market implements TDD.
The data rate is so dramatic compared to UMTS or GPRS that a rival operator is going to feel that.
A recent report from research house ARC Group said that operators are already thinking about the post-3G world. The technologies making the largest immediate impact on the post 3G world will be the upgrades to 3.5G and the integration of WLAN into wide area networks, the report said..
TDD, along with HSDPA, is one of the “3.5G” technologies that will drive 3.5G subscriber numbers up to 9.1 million by 2008, ARC said.
ARC said that HSDPA is expected to become the most popular of 3.5G technologies due to its support from major vendors like Nokia. HSDPA uses adaptive modulation and a new shared downlink transport channel type to achieve a two-fold increase in air interface capacity and a five-fold increase in data speeds in the downlink direction.
PWLAN will be subsumed into the network mix, supplementing the 3G/3.5G network for data intensive applications. Despite this, mobile subscribers using PWLAN services over their mobile device will only make up around 50 million users by 2008, less than 20% of total 3G subscribers.
Chris White, Telecoms Consultant at ARC said, “Too much attention has been paid to how PWLAN will compete with 3G rather than looking at the benefits of combining both network technologies. Further integration of WLAN into the mobile network mix is one of the vital stepping stones to 4G. The so-called access pyramid model, where multiple networks coexist allowing users to seamlessly switch between the most appropriate network for the device and situation, will not substitute the need for a 4G network. At the heart of everything will be the core network, be it 3G or 4G, which will be supplemented by PAN and WLAN offerings and by network upgrades in the medium-term.”