Improving timeliness and reliability of data delivery in tactical wireless environments with Mockets communications library

Network centric warfare relies on the timely and reliable delivery of data to disparate cooperating nodes in tactical networking environments. Given the limited bandwidth available and the unreliability of network links, data often accumulates in application and/or network queues, resulting in increased latency in the delivery of the data. The Mockets communications library addresses this problem via dynamic message replacement. The message replacement functionality of Mockets allows the system to drop all but the most recent message within a specific message flow by removing older, outdated messages from the queues. This paper describes and evaluates, in the context of the U.S. Air Force's Joint Battlespace Infosphere (JBI) system, the timeliness of end-to-end delivery of data using the Mockets library. In addition to dynamic message replacement, other capabilities in the Mockets library include options for reliable vs. unreliable and sequenced vs. unsequenced delivery of data, detailed statistics and feedback regarding the connection, and assignment and dynamic adjustment of priorities of messages. This paper provides a qualitative analysis of these different capabilities and their suitability to address the transport requirements in JBI. It also provides a quantitative comparison of Mockets with SCTP and SCPS-TP, which are similar technologies with existing available candidate implementations. Our results show that the Mockets library with the message replacement significantly outperforms these other transport protocols.