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There have been parallel technological developments in wireless local network (WLAN) and cellular wide area network (WAN) technologies. This is evidenced by the boom in fast WLANs enabled devices, the spread of 2.5 G networks and the increasing emergence 3 G communication networks, applications and terminals. The prospects of integrating WLAN and cellular WAN technologies with support for seamless handoffs between the two heterogeneous have changed the mentality of researchers from considering WLAN technology as a threat to the future of wide area cellular networks to accepting the technology as a complementary solution. A number of architectures for interworking the two different network types have been proposed mainly based on the loose coupling interworking approach recommended by the ETSI. One of the main weaknesses anticipated with loose coupling architecture is excessive handoff latency, which may lead to data loss, traffic congestion and handoff failure. In this paper an architecture for interworking WLAN and the GPRS networks, based on the ETSI tight coupling approach, is proposed.

In this paper, a novel approach is proposed to address the load-forecasting and expansion-planning process focused on long-range aspects. Depending upon land-use, five different user classes are considered. The existence of these classes and their associated boundaries are modeled with trapezoidal distribution. To find the relative share of one particular user class with remaining classes, a class composition vector is proposed. Further, dividing all the area segments into small square shaped cells of 40-acre size, the small area growth trend is estimated with 'S-shaped' curve for 20-year period. Here a piece-wise linear model is used to model the growth ramp segment of "S-shaped" growth characteristic. Finally two indices are proposed, one to estimate the new load demand, and other index to estimate the growth. The results obtained match the typical growth trend of different user classes for a practical distribution system.

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This study presents the performance analysis of a new tight coupling based WLAN/GPRS interworking architecture. The effects of network traffic on downward handoff latency are investigated. The results indicate that increasing WLAN traffic increases the overall downward handoff latency more than increasing GPRS traffic. On the other hand, increasing GPRS traffic results in higher packet buffering requirements at the Serving GPRS Support Node (SGSN).