A unified notification service utilizing explicit wireless degradation notifications

The dynamic characteristics of heterogeneous networks require cross layer solutions to optimize performance. Many cross layer solutions however, have tightly coupled Upper Layer Protocols (ULP) to lower layer performance metrics. Such an approach hinders the introduction of potential performance enhancements. In this paper we propose a Unified Notification Service (UNS) which will enable cross layer solutions while decoupling ULPs from lower layer performance metrics. UNS is designed as an open extensible framework to accommodate both existing and emerging notification plug-ins. UNS will also enable the integration of existing protocols to form new notification types. We illustrate how the general purpose solution provided by UNS can incorporate a new Wireless Degradation Notification (WDN) plug-in. We compare the performance of MAC layer retransmissions and Received Signal Strength (RSS) as network performance indicators, and illustrate that a retransmission based metric outperforms an RSS based approach.