Quality of Service Requirement in Wireless Sensor Networks: A Survey

Wireless Sensor Networks (WSN) is a prominent area of new interests and research. Advances in technology and availability of tiny, inexpensive sensors pave the way for intelligent life. WSN has applications in military, healthcare domains. Also, there are numerous operations where accurate and timely delivery of the sensed information is necessary. So, reliable and timely delivery of sensed information is the primary requirement of WSN. Quality of Service (QoS) provision usually consumes energy but energy is a scarce resource in WSN; so QoS based routing algorithms should be energy efficient. In this survey, numerous QoS based routing protocols are summarised. The main objective of the paper is to highlight the changes in methodologies used to develop QoS based routing protocols in WSN. Protocols developed in early stage did not consider energy as one of the metric, so these protocols were not energy efficient. Also most of the protocols are using the multipath mechanism for packet transfer. Prominent protocols which are capable of providing QoS in WSN are reviewed with their pros and cons. The paper ends with significant points observed during comparison of protocols, with the comment on possible directions towards development of ideal QoS based routing protocol required in WSN.