Nortel Networks Switches GSM Connections

Author: Carol Anderson & Howard Forryan


The future of mobile telephone switching looks very promising for Nortel Networks. With a little assistance from HARTING a committed development team has designed the XA-CORE (eXtended Architecture Core), a multiprocessor system for the familiar DMS 100 series of central office switches designed for the huge switching requirements of the new millennium.


Harold Graham, director of Nortel Networks' "SuperNode Computing Development, Carrier Solutions" explains, "The rate at which digital subscribers are joining networks around the world makes it imperative that we double and triple the number of subscribers we can support on a single mobile switching centre. XA-CORE is vital to the GSM (Global System for Mobile Communications) business. The key element of XA-CORE is its multiprocessor architecture that provides power to add more subscribers to the switching system, which is what our customers are demanding."


Around three hundred Nortel Networks employees from Ottawa and Raleigh were involved in the development of XA-CORE, which presented them with a considerable technological challenge. The need to develop a midplane solution enabling data to be transmitted at sufficient speed to keep real time-intensive applications operative is just one example. Another problem lay in the specified minimal space requirement of the midplanes. Therefore Nortel Networks needed a high packing and connection density and at the same time the guarantee of secure and very fast signal transmission.


Because of its high pin density with maximum transmission speed, the har-pak® Mini Coax connector system from HARTING offered an excellent basis. Therefore Nortel Networks and HARTING decided on a joint program to develop a 10-way Mini Coax connector that was to have 2 x 5 rows in a specified cross sectional area. To keep the time-to-market as short as possible Nortel Networks set a tight schedule. The HARTING product development and design team was able to meet these requirements in full.


The successful conclusion of the joint development program provides Nortel Networks with a midplane that can transmit a data rate of up to 112 Gbps. To process calls the 16 processors access a total 1.7 GBytes of memory capacity (shared memory). XA-CORE will come onto the market in the second half of the year. Leading international telecommunications service providers are waiting with anticipation.