MWSN routing protocols generally take influence from both WSN and mobile ad hoc network (MANET) routing protocols, which all share common limitations, such as bandwidth, power and cost. WSNs often share the same aim as MWSNs, in that they wish to route data from many sensors to a single sink. However, WSNs are normally considered to be static and so the associated routing protocols are often unable to cope in a mobile scenario [10]. Alternatively, MANET protocols are designed to be able to cope with the mobility of nodes, however they aim to allow end-to-end communication to occur between any two nodes [2]. This extra functionality is often not required by MWSNs and so the additional overhead is unnecessary. Combined with the high packet delivery ratios and low delays that are demanded by emerging applications, the ideal routing solution for a MWSN is one that can handle the mobility of nodes and allows data to be forwarded from the sensors to the sink in a reliable and timely manner. This set of requirements make the problem of routing in a MWSN a unique challenge, which will require new specifically designed solutions. For this reason there have been many routing protocols designed for MWSNs. As such, this section will give an overview of the current literature, which highlights the different techniques and commonly used protocols in MWSN routing.
