NetMon: Network Monitoring in Wireless Mesh Networks

Optimization of protocols in wireless networks often involve understanding and altering the lower layer phenomenon. The netmon utility is used to monitor the network characterstics at lower levels such as PHY and MAC layer.

PHY layer link quality monitor (PHYMon): Link quality forms a fundamental parameter that is used by the higher level applications and protocols to improve the performance of the network. Several models and simulations have proposed expressions to compute the approximate link quality. However, these cannot be directly used in realistic networks, wireless channel is strong function of the surrounding environment, and experiences dynamic changes that are not captured by the models. Hence, estimating the link quality in realistic wireless networks is an important aspect of designing efficient higher layer applications and protocols. In realistic wireless networks, link quality is generally predicted by measuring received signal strength and error rates. Understanding the temporal properties of these parameters is essential for the measured values to be representative, and for accurate prediction of performance of the system. In this project, we have two main aims:

  1. Understanding statistical properties of link quality: We analyze the received signal strength and error rates in an IEEE 802.11 indoor wireless mesh network, with special focus to understand its utility to higher level protocols in a wireless system. We monitor and analyze the statistical distribution and memory properties
  2. Describe a real-time link quality measurement architecture: We describe real-time measurement framework that enables several applications on wireless testbed, and discuss example applications that utilize measurement of signal strength and error rates

We plan to extend the above study by creating a frame work for "CSMA based MAC layer interaction detection", and then to extend the PHY and MAC layer measurement framework for higher level monitoring and provisioning applications.