Northern Telecom Ltd is to develop and manufacture the residential and base station equipment for use by Cambridge, UK-based Ionica L3 Ltd as the basis for its forthcoming UK telecommunications network. Observant subscribers will notice that the agreement bears a marked similarity to one announced in May (CI No 2,162), but Northern Telecom says that in May it merely started discussing the project with Ionica, and that the contract has only now been signed – apparently in May two competing press release distribution services made identical editing mistakes to an announcement that Northern Telecom had sent them, by changing the wording to say that everything was finalised. Northern Telecom has, however, been rather more forthcoming than Ionica on the exact nature of the technology: its main difference from existing cellular techniques is that it is based on fixed rather than mobile links: this is said to cut down on network overheads (such as the hand-off between cells), and also to allow for more secure links between the subscriber and the base station since the customer’s antenna is aimed directly at the base station.

Omnidirectional

It uses Time Division Multiple Access techniques, with each base station said to support several hundred subscribers. The base stations, which are omnidirectional, are said to have a range of around three miles and to be less bulky than standard cellular base stations; according to Northern Telecom they can be housed within a six foot cabinet. Links between the base stations and the local exchanges are to be provided via cable or microwave links. The customer equipment is said to consist of an octagonal flat plate antenna, around 11.5 in diameter, and around 0.2 thick. Ionica was granted a licence to use frequencies in the 3.5GHz range as part of its Public Telecommunications Operator’s licence. While the air interface used by the system is proprietary, Northern Telecom says that Ionica is keen that it should be adopted as a standard for fixed wireless links, and to that end the company has proposed this to the relevant European Telecommunications Standards Institute committees. It has also been revealed that Ionica plans to provide only the local connection to subscribers: calls will then be routed over the British Telecommunications Plc or Mercury Communications Ltd networks, and Ionica is in negotiations with the carriers on interconnection terms. According to the Yankee Group Europe in its White Paper on Wireless and Mobile Communications (and not confirmed by Ionica), the company does, however, plan to install its own local exchanges to bypass other carriers completely on local calls. Customers of the Ionica service – which is to be aimed at residential and small business users – will receive two lines as standard, and in addition Northern Telecom says Ionica plans to introduce an ISDN service; it says that the base stations will support ISDN, but that the customer terminal equipment needs modifying, a process that is under way. The Yankee Group is broadly optimistic about Ionica’s chances of success, pointing to the endorsement of Northern Telecom and Telecom Finland (which also announced in May its plans to use it) as evidence of its viability. The consultancy does, however, express a few reservations, specifically because Ionica is not disclosing how it intends to structure charges for the service, and what the tariffs will be (although Yankee Group believes charges could be 20% below British Telecom’s, and perhaps as much as 40%). Furthermore, it expresses concern that the technology is commercialy untested and that it is not known how high the call quality will be; that while it is said to support facsimile machines and modems it is limited in its ability to transmit high-speed data; that there may be line-of-sight prob-lems in some locations, for example in blocks of flats, although Ionica claims that this should be a small number; and that Ionica’s roll-out schedule is confidential. Ionica plans to start user trials next year – probably near its Cambridge headquarters – w

ith the service to launch commercially in the first quarter of 1995. Ionica says network roll-out will then take place on a region-by region basis, although it would not say which areas it will be going into initially.