Time-Critical Transmission Protocols in Wireless Sensor Networks: A Survey

Abstract

Wireless Sensor Network (WSN) is an extremely important tool for closely monitoring, understanding and controlling application processes to the end users. The main purpose behind installing the wireless sensor network is to make real-time decisions based on data received from the sensor nodes. This data transmission from sensor nodes to the base station is considered to be very complicated because of the resources and communication capability constraints of various sensor nodes and enormous amount of data is generated by WSNs. Real-time applications in WSN like mission-critical monitoring, surveillance systems, etc., demands well-timed and reliable delivery of data. For such applications, besides energy, Quality of Services (QoS) routing, i.e., requirement of message delivery timeliness is also one of the significant issues. Based on the type of application, it is essential to grant different levels of QoS in WSNs. In this paper, QoS requirements for mission-critical WSNs applications are highlighted and existing QoS-aware protocols to support such applications are discussed with their boundaries in that domain.