Optimized Routing in Organization-Aware Multihop Wireless Networks (ORION) Lijun Qian Department of Electrical and Computer Engineering Prairie View A&M University, Texas A&M University System Prairie View, Texas 77446, USA Email: liqian@pvamu.edu Yuanzhu Peter Chen Department of Computer Science Memorial University of Newfoundland St. John’s, NL Canada Email: yzchen@mun.ca Abstract—In our previous works, we defined a novel routing metric for organization-aware multihop wireless networks [1]. We demonstrated that our proposed routing protocol with this new metric provides the much needed survivability and efficiency in battlefield environments when keeping the cross-organization data transfer at a low level [2]. In this paper, we take one step further and propose ORION, a framework for quality-of-service (QoS) routing in organization-aware wireless networks. Here, we formulate routing as a constrained optimization problem with a new routing metric to address QoS and security/policy requirements of traffic flows as well as node-specific needs, while taking the organizational constraints into account. Since the problem is not solvable in polynomial time, a near optimal solution procedure based on Lagrangian decomposition and sub- gradient method is proposed and studied to solve the constrained optimization problem, and such a solution renders itself to distributed implementations. Simulation results show that the proposed method provides high QoS while keeping the cross- organization data transfer at a specified level satisfying strict organizational security constraints. I. I NTRODUCTION In many mission critical applications, such as military op- erations and first responder efforts, multiple organizations are usually involved in the mission. For instance, national guard, firefighters, emergency medical services can be deployed to a disaster region after a severe earthquake. Typically, mobile ad hoc networks (MANETs) are deployed in real time for com- munications since either the infrastructure may be destroyed or it cannot be accessed. However, different organizations could have heterogeneous wireless networking devices and, yet, information sharing among them plays a pivotal role in saving lives and maximizing operation efficiency. As a result, inter- operability among the participating organizations is highly desirable for sharing information and effective collaborations. The emerging software defined radio (SDR) platform pro- vides an enabling technology for future inter-operable wireless networks used by different organizations [3]. In this paper, we consider the scenario of heterogeneous MANETs deployed within the same geographical area, and assume that all the nodes are inter-operable. Specifically, we focus on the routing problem in scenarios where nodes of one organization can help to transport traffic for nodes of a different organization. This is crucial for maintaining survivability and efficiency in a harsh environment. For example, as illustrated in Fig. 1, the soldiers and the sensors belonging to two different organizations but their radios are inter-operable. Assume that soldier D is out of the radio range of its own network. D could only communicate with other soldiers through sensor node 1. Moreover, in many cases, more efficient communication may be achieved through collaborations among different organizations. Again, as in the figure, if sensor node 2 has little remaining battery power, we must route the sensed data via other nodes. Without cross- organization data forwarding, we must take the route of 3-4- 5-Fusion Center. However, if the help of the soldiers can be used, it would be more efficient to transport through a shortcut via soldier A. Fig. 1. Collaboration in an organization-aware mobile ad hoc network Although there can be considerable benefits for different or- ganizations to collaborate in data transfer, it is crucial that the incurred additional overhead to the helping organization will not degrade its own operation significantly. More importantly, the nodes within or outside the same organization may have different security or policy requirements. For instance, suppose that soldier A in Fig. 1 has strict security requirement. In this case, it may not be appropriate for him to relay traffic for the sensor nodes. In our previous works, we defined an organization-aware routing metric for multihop wireless networks [1]. We demon- strated that such a metric indeed provides the much needed The 2010 Military Communications Conference - Unclassified Program - Networking Protocols and Performance Track 978-1-4244-8180-4/10/$26.00 ©2010 IEEE 629