682 IEEE TRANSACTIONS ON SYSTEMS, MAN, AND CYBERNETICS—PART A: SYSTEMS AND HUMANS, VOL. 33, NO. 6,NOVEMBER 2003 Konark: A System and Protocols for Device Independent, Peer-to-Peer Discovery and Delivery of Mobile Services Choonhwa Lee, Member, IEEE, Abdelsalam Helal, Senior Member, IEEE, Nitin Desai, Varun Verma, and Bekir Arslan Abstract—The proliferation of mobile devices and the pervasive- ness of wireless technology have provided a major impetus to repli- cate the network-based service discovery technologies in wireless and mobile networks. However, existing service discovery proto- cols and delivery mechanisms designed for traditional infrastruc- ture-based networks fall short of accommodating the complexities of the ad hoc environment. Konark is a service discovery and de- livery protocol designed specifically for ad hoc, peer-to-peer net- works, and targeted toward device-independent services in gen- eral and m-commerce oriented software services in particular. It has two major aspects-service discovery and service delivery. For discovery, Konark uses a novel decentralized, peer-to-peer mecha- nism that provides each device the ability to advertise and discover services in an efficient way. The approach toward service descrip- tion is XML-based. It includes a description template that allows services to be described in a human and software understandable forms. A micro-HTTP server present on each device handles ser- vice delivery, which is based on SOAP. Konark provides a frame- work for connecting isolated services offered by proximal pervasive devices over a wireless medium. Index Terms—Ad hoc networks, m-commerce, pervasive com- puting, service discovery protocols. I. INTRODUCTION T HE LAST few years have seen a rapid increase in the usage of mobile devices such as laptops, cell-phones, and per- sonal data assistants (PDAs) [1]. The accompanied maturity in wireless technologies such as IEEE 802.11 has made wireless networks almost as ubiquitous as traditional wired networks. An important consequence of such developments has been the con- cept of ad hoc networks [2]. These networks are characterized by their lack of required infrastructure and ease of formation; each participating device is mobile and the networks are formed temporarily. For example, a network formed when a group of people comes together in a conference, in an emergency relief scenario, or in an airport lounge. As the “deployment” and usage of such networks increase, new paradigms begin to emerge that incorporate and utilize these new communication capabilities in ways that were previously not thought of or were impossible to Manuscript received January 31, 2003; revised May 23, 2003. This paper was recommended by Guest Editors Z. Maamar and B. Benatallah. C. Lee, A. Helal and B. Arslan are with the Computer Science and Engi- neering Department, University of Florida, Gainesville, FL 32611 USA (e-mail: chl@cise.ufl.edu; helal@cise.ufl.edu; barslan@cise.ufl.edu). N. Desai and V. Verma are with Citrix Systems, Fort Lauderdale, FL 33309 USA (e-mail: Nitin.Desai@citrix.com; Varun.Verma@citrix.com). Digital Object Identifier 10.1109/TSMCA.2003.819493 implement. Some of the possible applications and scenarios for ad hoc networks are as follows: • using your wireless handheld device, the ability to not only locate a nearby restaurant serving your favorite Chinese food, but also reserve a table and order your food before walking to it. • an application on your handheld device that packages your personal expertise of being a web-security consultant as a service, advertises this service in relevant places like technical conferences, and responds to searches for such services with more details such as your current location, your schedule, and how much you charge for a consulting session. • the ability to share with others entertainment sources such as music and games available on your personal handheld device. Such a capability would be extremely useful while waiting for a flight in an airport lounge, or other similar situations of killing time in a public place. In all the above-mentioned scenarios, the resources being shared or searched are packaged as services. As evident, services can be those offered by devices (e.g., printers, fax machines), or simply software services that are device in- dependent. Even software services offer a myriad range of possibilities with opportunities related to an individual’s career, entertainment, or daily chores like ordering food. The feasibility of above scenarios requires not only the for- mation of ad hoc networks and packaging of resource as ser- vices, but also a discovery and delivery mechanism suited to the needs of ad hoc networks and geared toward m-commerce oriented services. Low-level technologies necessary to form a peer-to-peer, ad hoc network are available. The missing link is a higher-level framework and protocol, which will enable devices to discover and advertise their services over ad hoc networks. To address the new opportunities, issues, and requirements, we present Konark, a middleware designed specifically for discovery and delivery of device independent services in ad hoc networks. Konark is based on a peer-to-peer model with each participating device having the capabilities to host its local services, deliver its own services using a resident micro-HTTP server, query the network for available services offered by others, and use the services it discovered in the network. We start this paper by discussing dynamic service discovery in general, followed by the issues we considered during the de- sign phase of Konark. We then present the Konark architectural design and implementation and an evaluation of our proposed 1083-4427/03$17.00 © 2003 IEEE