The handoff control scheme for computing powerless devices and its applications in the digital home network

The evolution of wireless transmission technology enables users to have multimedia services anywhere in the digital home network. In this paper, we propose a handoff control scheme called Computing Powerless Handoff (CP-Handoff) for devices without computation capability, such as the light-weight Bluetooth (LW-BT) headset. The main concern of the CP-Handoff is that the client device doesn't have the computation capability. The main function of the computing powerless client device is to send/receive signals and play the audio data. Thus, how to have the handoff control when a computing powerless client device is switched from one access point to another access point becomes a problem to be resolved. A typical example is in the BT wireless network environment. The LW-BT headset is dedicated for audio applications and doesn't have extra computation capability. The CP-Handoff puts all handoff computation overhead on the master BT device, such that the LW-BT headset is unaware of the handoff. Based on the proposed CP-Handoff control scheme, a Ubiquitous Audio Access Platform (UAAP) is proposed and developed to allow users to access audio files using the LW-BT headset in the digital home network when they are roaming. The evaluation results show that the proposed CP-Handoff only needs 1.17 s to prepare the AVDTP session handoff and 0.38 s for the AVDTP session handoff. The transmission of audio packets to the LW-BT headset is only suspended for 0.38 s. The audio packet buffering scheme and retransmission mechanism ensure that the LW-BT headset can resume lost audio packets during handoff. Crown