V. Sundramoorthy

Service discovery at home

Service discovery is a fairly new field that kicked off since the advent of ubiquitous computing and has been found essential in the making of intelligent networks by implementing automated discovery and remote control between devices. This paper provides an overview and comparison of several prominent service discovery mechanisms currently available. It also introduces the at home anywhere service discovery protocol (SDP@HA) design which improves on the current state of the art by accommodating resource lean devices, implementing a dynamic leader election for a central cataloguing device and embedding robustness to the service discovery architecture as an important criterion.

On consistency maintenance in service discovery

Communication and node failures degrade the ability of a service discovery protocol to ensure users receive the correct service information when the service changes. We propose that service discovery protocols employ a set of recovery techniques to recover from failures and regain consistency. We use simulations to show that the type of recovery technique a protocol uses significantly impacts the performance. We benchmark the performance of our own service discovery protocol, FRODO against the performance of first generation service discovery protocols, Jini and UPnP during increasing communication and node failures. The results show that FRODO has the best overall consistency maintenance performance

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.

Functional Principles of Registry-based Service Discovery

As service discovery protocols (SDP) are becoming increasingly important for ubiquitous computing, they must behave according to predefined principles. We present the functional principles of service discovery for robust, registry-based service discovery. A methodology to guarantee adherence to these principles is provided and illustrated by formal verification of the principles against FRODO, an SDP built for the home environment. We show that, to make behavioral guarantees, an SDP has to be robust against network disturbances, and cannot rely only on the network layer