Sensor array networks and long distance communications

This paper will discuss the on-going research at Army Research Laboratory (ARL) supporting long distance communication for networked sensor arrays. As the Army continues to move forward in the development of remote, distributed, unattended, intelligence sensors, the need for the resultant information to reach the command and control center increases. In the case of sensor array networks the command and control center provides configuration information for deployment and battlefield visualization tools to interpret and integrate the data received. These sensor array networks may be separated by long distances from the command and control center. To allow the communication to take place, an experimental long distance communication link was developed and demonstrated. The link consists of a variable node ad-hoc wireless network and controlling software. This network provides the pre-processed data for situational awareness to the remote command control center over a low bandwidth link. This link must be robust in that it must tolerate node failures and adapt. Although mobility is not a large issue, the network must tolerate a variable network topology and must therefore be ad-hoc. In this paper we will discuss the design requirements for this communication link along with the protocols developed to overcome limitations imposed by the noisy, failure prone battlefield wireless environment. We will also discuss the software and hardware architecture design and implementation for the generalized long distance sensor array communication link. Currently, operational components of this link function over an 80 mile distance with very high noise levels, node failures, intermittent connectivity, and severe bandwidth constraints.