Evaluation of Middleware for Bandwidth Aggregation using Multiple Interface in Wireless Communication

Although a variety of wireless interfaces are available on mobile devices, they still provide only low throughput so far. When coverage areas of those different technologies overlap, mobile devices with multiple interfaces can use them simultaneously by mechanism of Bandwidth Aggregation. However, there are some performance problems for Bandwidth Aggregation on Network Layer and lower Layer which derive from TCP congestion control mechanism. If Bandwidth Aggregation is performed at a layer lower than Transport layer, a packet loss happend in one route should decrease performance of all routes because reducing TCP congestion window on such a case affects communications of all routes. Thus we have proposed advanced Bandwidth Aggregation on Middleware for the purpose of avoiding there problems. If Bandwidth Aggregation is performed at Middleware that locates between Transport layer and applications, TCP congestion windows can be managed separately as route by route. In this paper, we have evaluated Middleware for Bandwidth Aggregation, which includes throughput and buffer size of receiver Middleware. According to the evaluation, it is possible to prevent from performance degradation when a packet loss happens using Middleware with an appropriate size of buffer at receiver-side. Keywords-component; Bandwidth Aggregation; Multiple Interface; Middleware; Buffer Size; IEEE 802.11; TCP Congestion Window