The Performance of the corDECT Voice/Data Wireless Local Loop

The traditional wired local loop used to connect each telephone subscriber to the nearest exchange is expensive and unreliable. Wireless Local Loop (WLL) systems largely eliminate these copper wires using wireless technologies and could provide a cost effective solution. corDECT is one such WLL system, based on the DECT (Digital Enhanced Cordless Telecommunications) standard, that provides toll-quality voice and data capability at a cost well below that of a wired local loop. A closed Queueing Network Model (QNM) is proposed for the corDECT system. The model is validated against actual measurements. Our model predicts that the 1,000-line corDECT system would meet a Busy Hour Call Attempt (BHCA) of 36,000 calls/hr, which is far greater than its requirement of 20,000 calls/hr. The bottlenecks that limit the BHCA to 36,000 calls/hr were identified by the model. We show how the system could be expanded to a 10,000-line exchange with a BHCA of over 2,10,000 calls/hr. We also investigate the feasibility of implementing 64 kbps data service along with voice. It is shown that this requires modest hardware improvements.