One of the key design issues for the new generation IP routers is the route lookup mechanism. For each incoming IP packet, the IP routing requires to perform a longest prefix matching on the address lookup in order to determine the packet's next hop. This paper presents a fast route lookup mechanism that only needs tiny SRAM and can be implemented in a pipelined skill in hardware. Based on the proposed scheme, the forwarding table is tiny enough to fit in SRAM with very low cost. For example, a large routing table with 40,000 routing entries can be compacted to a forwarding table of 450-470 Kbytes. In the worst case, the number of memory accesses for a lookup is three. When implemented in a pipeline skill in hardware, the proposed mechanism can achieve one routing lookup every memory access. With current 10 ns SRAM, this mechanism furnishes approximately 100 million routing lookups per second. This is much faster than any current commercially available routing lookup schemes.

The initial cost to provide personal communications services (PCS) based on the conventional networks is relative high. As the radio cells move toward smaller size, the traditional procedures for call setup and control are not suitable well due to the high handoff frequency. The cable TV (CATV) network is one of the most attractive backbones for PCS due to its prevalent and broadcast nature. This significantly reduces the implementation costs and the handoff overheads. This paper proposes two architectures for the CATV-based PCS system. In the first architecture, each base station is equipped with multiple fixed receivers to provide fast and seamless handoffs for mobile terminals. Nevertheless, it suffers from the expensive hardware cost. In the second architecture, each base station is only equipped with one tunable receiver. This simple and economic architecture suffers from the possibility of offset conflict when mobile terminals handoff between the cells. Three channel allocation algorithms are proposed to resolve the offset conflict problem. Simulation results indicate the one with the concept of clustering performs much better than the other two schemes in terms of offset conflict probability.

Many multimedia applications require guaranteed quality of service (QoS) in communication networks. Typically, the QoS includes bandwidth, delay, and delay jitter. This paper presents a real-time protocol to support multimedia communications in which the connections are established with efficient resource reservation and proper admission control. During data transmission, the rate, jitter control, and packet scheduling techniques are employed to fulfil the performance contract. The protocol also incorporates a multicast function to provide group communications. This protocol is implemented on a high-speed network which consists of interconnected ATM switches, FDDI networks, routers, and hosts. Experiments have been carried out to evaluate the effectiveness of the QoS guaranteed protocol. Measured results indicate that the proposed protocol performs well to guarantee the QoS in terms of the bandwidth, delay, and delay jitter.