A Cost-Effective Two-Way Household Wireless Door Intercom System

This study utilized a wireless transceiver module (NRF24L01) and ATmega328 to implement a cost-effective household door intercom. The intercom consist of two units; the outdoor and indoor. The outdoor unit was used by the guest to communicate with the household owner to notify them of their presence at the door while the indoor unit was used to respond to the call. The transceiver module transmits and receives audio signals between the two units, while ATmega328 handles the conversion of the signal from analog to digital during transmission and vice-versa at reception. The outcome of the test and analysis carried out on the developed prototype shows that it is user-friendly, consumes less power, and also proves that it is a cost-effective solution that can be affordable and made to be readily available to the consumer.

Research on QoS Guarantee Technology for Intercom System Based on SIP

Theatre intercom system based on SIP has solved the defects of traditional theater scheduling, but it doesn't guarantee the quality of service (QoS). This paper introduced the key technology for SIP-based theatre intercom system, including the fundamentals of VOIP and signaling technology. We analysed the main factors influencing QoS, summarized correlative techniques improving QoS for theatre intercom system, including QoS relevant protocols and QoS guarantee technology on terminals. These technologies can be synthetically used, so as to improve the reliability of theatre intercom system.