Lucent Technologies Spotlights New TDMA Strategies

Murray Hill, NJ-based Lucent Technologies disclosed three technical initiatives designed to increase capacity while preserving wireless network operators' investments in existing TDMA equipment.

During the Universal Wireless Communication Consortium's (UWCC's) Global Summit, Lucent announced a series of software enhancements developed by Bell Laboratories (Madison, WI) researchers to increase frequency re-use and thereby reduce the number of TDMA base stations required to provide wireless service in any given geographic area. To develop these enhancements, Lucent has tapped into Bell Labs' work in intelligent antennas, downlink dynamic power control, flexible channel allocation, discontinuous transmission, and expanded use of hierarchical cells.

The enhancement software allows TDMA radios to use identical radio frequencies in closer proximity to one another without causing interference, enabling service providers to make more efficient use of their finite licensed spectrum. These enhancements will be offered through periodic software updates to Lucent's TDMA wireless platform, starting in mid-1999.

Growth Path
During the conference, Lucent also introduced new PCS Minicell growth hardware that provides high capacity for traffic-intensive urban centers.

The growth cabinets will incrementally increase the capacity of its current Autoplex TDMA PCS Minicell. Through "hot-sector loading," the Minicell can support 32 radios in one sector. Lucent plans further incremental improvements that will eventually enable the TDMA PCS Minicell to support up to 96 radios, or 288 digital channels.

The initial growth cabinets will be available this year. They will support up to 48 radios, or 144 digital channels, per cell.

A new scheme
In one final release, Lucent said it would propose a new digital voice-coding scheme able to effectively double voice capacity within existing spectrum to standards organizations. According to the company, the new voice coding scheme can effectively double the number of voice calls, even at the fringes of coverage of IS-136 base stations.

Lucent said it would take its proposal to standards bodies that are now considering ways for improving the current speech processor to handle more voice calls without degradation in speech quality. Lucent's proposal incorporates new voice coding, channel coding, and interleaving techniques developed by Bell Labs researchers.