Multimedia QoS in low-cost home networks

This paper describes a new mechanism to guarantee quality of service for multimedia streams in low-cost home networks. Quality of service is based on a token, of which the route in the network is determined by a distributed scheduler. The network node that has the token-the active node-can send its data during a predetermined period. The length of this period and which the node gets the token next is calculated by the scheduler in the active node. Every node has a scheduler on-board and schedules streams according to stream information from other nodes-contained in the token-and its own streams. Although other types of scheduler could be used, the token scheduler deploys a preemptive earliest deadline first strategy. This guarantees a theoretical maximum bandwidth utilization of 100 percent. The network is simulated and a prototype is built, based on low-cost ethernet hardware. Results show a high throughput with a small overhead of less than one percent per stream.