No abstract

TCP is a popular internet protocol for reliable end-to-end data delivery, but it cannot be applied to wireless networks in which packet loss may be induced by higher BER or handover than congestion. It assumes that such packet loss is caused by network congestion and initiates congestion control procedures. In this paper, we present a novel protocol using Explicit Handover Notification to improve TCP performance over wireless links. Additionally, we execute simulations using network simulator and compare the simulated protocols.

SUMMARYRecently, attention has focused on multihop wireless networks capable of expanding the communication area by employing wireless relays between nodes and access points. However, the problem in a multihop wireless network is differences arise in the throughput caused by the number of hops from the base station connected to wired networks. In this paper, we propose a scheduling algorithm which solves this problem. In this proposal, the uplink packets and downlink packets are queued separately, and the uplink packets are classified into packets originated within the node and forwarded packets from adjacent wireless nodes and queued. When the node transmits a packet, the fairness among the nodes is improved by scheduling based on the source identifiers of the queued packets. The results of a performance evaluation using a network simulator verified a maximum tenfold improvement in the fairness among the subscribers compared to typical schemes.

No abstract

When an indoor coverage area is designed in mobile communication systems, it is important to estimate the received power from an outdoor base station in order to evaluate the interference level indoors. This paper evaluates outdoor-toindoor radio propagation with 800 MHz band through measurement campaigns at the lower multiple floors of some buildings in an urban environment. The evaluation result shows that propagation loss in an area close to a window does not follow the existing formula where loss is predicted in proportion to distance.