CDMA Technology
Members Sign-In
New Markets, New Trials, New Directions

CDMA firsts in Europe and India for Motorola, NTT plans wideband trials in Japan and Qualcomm links up with Vodafone for CDMA/GSM integration trials.

The Second Annual CDMA World Congress in Singapore might seem a strange place to hear about an important breakthrough involving a GSM operator. Nevertheless, it was at this conference that delegates heard more about IS-95 inventor Qualcomm’s planned field trial with UK and international operator Vodafone to demonstrate the integration of a CDMA air interface with a GSM network. The companies plan to demonstrate the capability of the GSM-A interface to support CDMA as an alternative access technology.

The system trial will take place in Newbury in the UK. Qualcomm will provide four CDMA commercial base stations and a base station controller; Vodafone will provide base station sites and a Mobile Switching Centre.

Modified Qualcomm 1.9GHz PCS phones will be used for the trial while The Technology Partnership, a UK company, will supply the GSM phone software. The CDMA phone hardware has been modified to accommodate standard GSM SIM cards. Installation of equipment has already begun, with the measurement phase expected to run from the fourth quarter of this year until the first quarter of 1998.

"The idea is to find out what the similarities and differences are between the two technologies, with an eye to developing a third generation standard. Our target is to identify a standard and offer equipment that will meet that standard," says Dr Chris Graeme-Barber of the Technology Partnership.

While Vodafone is emphasising that the CDMA trials will be helpful in evaluating the evolution to Third Generation systems, the company is nevertheless stressing that the existing IS-95 CDMA standard will not be its Third Generation platform.

As for Qualcomm, its Chief Executive Officer, Dr Irwin Jacobs, explained: "We’re planning, if all goes well, to hold a field trial toward the end of this calendar year. This first trial is to demonstrate technical feasibility. By that I mean using a phone that, to a GSM user, appears to have all the GSM features they are used to, including of course the GSM SIM card. The base station controller would be attached through the standard A-interface. The switch would basically not know that it’s utilising a CDMA air interface as opposed to a TDMA air interface."

The trials could, however, have other implications, as he acknowledges: "There’s also an effort ongoing to look at the economics of a CDMA air interface on a GSM network. This could provide information to help operators to decide, if this type of air interface were to be allowed, when and where it would make sense to utilise it."

The link between Vodafone and Qualcomm is not a new one. Both are founding partners of the Globalstar GMPCS satellite system for which Qualcomm developed the ground communications segment. As part of the Globalstar system design, a satellite-based CDMA air interface to the GSM network has been developed. From this starting point, the companies have defined a new concept for the integration of CDMA terrestrial radio access with the GSM network that is to be tested this year.

Globalstar representatives pointed out at the Singapore event that the company’s present plans call for no fewer than three handsets to be developed: a dual mode GSM/Globalstar phone, a tri-mode AMPS/ CDMA/Globalstar phone and a single mode Globalstar phone.

However, the integration trials may not affect Globalstar’s handset plans just yet, says Dr Jacobs: "I think the timing is such that one will still need, for example a GSM/Globalstar handset or a CDMA/Globalstar handset and others as well." That’s not to say it may never happen, he points out: "There will become more and more the possibility of dual mode, dual band and, hopefully in this case, IS-41 and GSM dual network type phones. But with Globalstar coming along at the current rate, one would have to have the dual capability (CSDMA/Globalstar or GSM/ Globalstar) phones near term."

A number of groups, notably the ITU, are working on standardisation and research leading, it is hoped, towards a next generation mobile communication system capable of dealing with the differing demands of voice, data and visual images. Japan’s Ministry of Post and Telecommunications (MPT), Association of Radio Industries and Business (ARIB), and The Telecommunication Technology Committee (TTC) are all playing a central role in the country’s own efforts to answer the question: what’s next?

NTT DoCoMo has been involved in these efforts and has now announced system tests of what it refers to as W-CDMA or wideband CDMA. It cites this as one of the most viable candidates for the next generation mobile communication system and one which might play a part in the standardisation process.

NTT points out that much research and discussion has already been going on in Japan into the next generation. The aim is, it says, to put a proposal to the ITU.

Progress has already been made with preliminary internal tests for W-CDMA in which the company has successfully carried out a radio transmission test of 2 Mbps. The next step is to verify its viability in the field.

W-CDMA, says NTT, meets a number of criteria essential for the next generation, notably transmission equal in quality to ISDN; high speed radio transmission (384 kbps for mobile; 2 Mbps for indoors); and highly efficient processing of multiple traffic, such as multiple rates and upward/downward asynchronous services.

NTT makes it clear that it sees W-CDMA as the technology best able to meet the needs of mobile multi-media communications.
So what happens now? The test itself will involve approximately six cell sites. The targets are to attain: high quality voice (approx. 8 kbps); modem transmission (28.8 kbps); unrestricted digital data transmission (64 kbps); packet data transmission (over 384 kbps); and transmission of moving pictures (at over 384 kbps). Tests for functionality will cover: sector structure; base station system structure; high speed cell search;diversity hand-over (DHO); random access; and ATM transmission.

All domestic and international cellular operators have been invited to get involved with the tests. To underline the commitment to internationalising the process, NTT points out that visits have already been made to operators in 15 or more countries.

A number of vendor companies have made proposals and been selected already. So far (and the company reserves the right to invite other manufacturers to participate), 10 companies have been selected. For the base station prototype, Ericsson, Fujitsu, Lucent Technologies, Matsushita Communication Industrial and NEC have been selected. For the mobile station prototype, the names to note are Matsushita Communication Industrial, Mitsubishi Elec-tric, Motorola, NEC, Nokia, Sharp and Toshiba. A separate track procurement procedure is planned for the commercial system, however.

Quick off the mark in letting the market know what it has to offer has been Ericsson. The company has announced that to support instant access to multimedia services, its wideband CDMA experimental system for DoCoMo will employ a new random-access procedure with fast synchronisation to handle the 384 kbit/s packet-data service. This, Ericsson believes, will reduce the time to establish connections between mobile users and base stations to a few tenths of a millisecond.

Other proposed highlights include specially designed spreading codes called Orthogonal Variable Spreading Factor codes (OVSF) which, says Ericsson, allow optimum flexibility and eliminate interference between users operating at different data rates on the same RF carrier, and the latest ATM minicell transmission protocol, known as ATM Adaption Layer 2 (AAL2). The protocol will be used for the transmission between the radio base stations and the mobile switching centre via the base station controllers.

The use of AAL2 will, suggests Ericsson, permit a greater number of data packets to be transmitted more efficiently and with less delay. Thus, data is transmitted only when the user is in an active session. This protocol permits large gains in call and data transmission, says Ericsson and while AAL2 provides the function necessary to perform a ‘soft’ hand-off between carriers, it also drastically reduces transmission costs.
Capacity, coverage and speed gains are all claimed for the system Ericsson is promoting. It will also incorporate new methods of deploying CDMA technology, including minicells and adaptive antennas.

Ericsson’s enhancements to code division technology for wideband applications include a novel hand-off method between wideband CDMA carriers. Called Inter-Frequency Hand-off (IFHO), this technique facilitates the use of low power microcells. IFHO also permits the stacking of microcells in an arrangement known as Hierarchical Cell Structures. Ericsson argues that this makes it possible, for instance, to use microcells to boost capacity in an office building, while at the same time using a macrocell installed at the rooftop.

Don’t forget, however, that NTT is still only at the trial stage with this technology — and other vendors will have their own solutions to promote. In fact, the CDMA Development Group has perhaps put NTT DoCoMo’s intentions to the test by stating its wish to cooperate with DoCoMo in developing the proposed next generation standard. At a recent Tokyo press conference, Perry LaForge, the CDG’s Executive Director noted that the CDG was having "open discussions" with NTT.

The question now is whether NTT’s system and manufacturers of cdmaOne systems can together find a way forward, given fears that the NTT system may not be backwardly compatible with cdmaOne.

NTT has stated that it aims to promote the tests in an open manner and "will cooperate with the standardisation activities in the world". The results of the tests will in fact be conveyed to the standardisation organisations and others.This will not be allowed to slow down progress, it seems. The scheduling is fairly precise. Prototype design will continue until the end of this year, with indoor testing planned from April, 1998 - March, 1999 and outdoor tests from October, 1998 - September, 1999.

The aim is to begin offering next generation mobile communication system services in the fiscal year 2000. In future issues, we hope to outline the plans — and hopes — of the major participants in these tests and what sort of impact the tests may have on next generation standardisation efforts.

For more information on possible ways forward for cdmaOne, see page 30.

Motorola's Cellular Infrastructure Group (CIG) has been awarded a contract worth $50 million by Poland's Telekomunikacja Polska S.A. (TPSA) to build the world's largest, and Europe's first, fixed and mobile converged services network using CDMA on Motorola's WiLL wireless local loop system.

By combining the cellular features of CDMA with the advantages of wireless local loop technology, up to 100,000 people in Poland will have a choice of either a fixed wireless connection to the home or the office or a limited mobility communications service using conventional CDMA personal phones.

Deployment of TPSA's 800 MHz network will begin in August, 1997 and will initially provide voice telephony, facsimile and data transmission services. Commercial service is scheduled to begin in September, 1997.

Once the existing waiting list for telephone services has been cleared, the TPSA anticipates that new applications will be processed virtually instantly and the time between submission of the application and the start of customer service should be only a matter of hours.
The new network will interconnect with the existing TPSA fixed network for local and international access and will conform to TPSA's national wireline numbering system.

Motorola CIG will provide a full turnkey system covering network design, project management, civil works,installation and commissioning of Motorola's SC 2450 cell sites, EMX 2500 switches and operations and maintenance center.
For fixed subscribers on the WiLL network, Motorola CIG's new 800SC CDMA Fixed Wireless Terminal (FWT) will provide supplementary services such as call forwarding and conference calling.

And that’s not all. Motorola CIG has been selected by Bharti Telenet, Ltd. to deploy India's first large-scale commercial CDMA digital fixed wireless WiLL telephone network. The initial deployment of the project is valued at more than $50 million.
Motorola CIG will begin de

ployment of the CDMA wireless local loop system this fall. Once commercial service begins, the system will serve the state of Madhya Pradesh, which has a population of 70 million and a current teledensity of less than one telephone per hundred people.
Bharti Telenet, Ltd. is the first of India’s Basic Services license holders to start network deployment and plans to be India's first private telephone operator.

Motorola CIG's WiLL system will operate in the 800 MHz frequency band using the V5.2 digital interface approved by the European Telecommunications Standards Institute (ETSI) standard for wireless local loop systems.

In a bid to expand their share of the domestic cellular market, Japan's two regional cellular giants, Nippon Idou Tsushin Corp. (IDO) and DDI Corp., are teaming up to offer integrated services. At present, IDO serves the Tokyo and Nagoya areas, while DDI Cellular's eight group firms operate in the rest of Japan.

This spring, IDO and DDI announced a deal to merge their operations in order to offer integrated, nationwide service based on cdmaOne. "The deal is long overdue," says Takeo Tsukada, IDO's president. The companies had already considered integrating services on two previous occasions.

Powerwave Technologies Inc. has announced that it has received an order to develop a 25 watt single carrier Personal Communications Services (PCS) amplifier for Qualcomm Inc. Powerwave is to supply to Qualcomm highly linear, 25 watt single carrier PCS CDMA amplifiers for use in Qual-comm's prototype testing of CDMA PCS base stations.
It is anticipated that these CDMA PCS base stations will eventually be utilized to provide network coverage for PCS network operators.

Lucent Technologies has announced that Ameritech Cellular Services has signed a five-year, multi-million dollar contract that makes Lucent the sole infrastructure supplier for Ameritech's wireless services, including its new ClearPath digital wireless service based on CDMA digital technology.

Lucent is to provide 5ESS-2000 switches and wireless base stations, as well as related hardware, software, and installation and engineering services for the entire infrastructure of Ameritech's ClearPath digital wireless network.

The contract also calls for Lucent to supply other equipment for Ameritech's offer of ClearPath Personal Communications Services (PCS). Ameritech will provide ClearPath PCS service to customers in the Cleveland and Indianapolis areas.