In this article we focus on SIP session setup delay .It bases on adaptive RLP retransmission mechanism in the previous paper.It proposes a way used RLP retransmission strategy combined with the performance of wireless channels, that i s to say in different chain Road conditions use different RLP retransmission strategy approach. This method not only can complete the RLP adaptive retransmission of SIP messages at the link layer, and can select the appropriate link status of the different RLP retransmission strategy, thus effectively shortening the SIP session establishment delay, end to end QoS for IMS performance improvement. After a simulation experiment, the effectiveness of the proposed algorithm is tested.

Family living environment plays an important role in people’s daily life. But the living environment monitoring system is difficult and complex to wiring, the bulky equipment is difficult to carry and install. As for these problems, this paper puts forward a wireless family living environment monitoring system using radio frequency chip NRF24L01 for 2.4GHz band and C8051F microcontroller, the system’s hardware and software design is discussed in detail. The system uses C8051F microcontroller as the core controller, the wireless transceiver chip NRF24L01 transmits the data acquired by sensors in real-time. The environment information will display on the LCD screen when the center host receives data from wireless extension and the exceeded parameters are alarmed. The system has low power, no wiring and easy to move feature.