This brief reviews the state of the art (as of the start of 2012) in research on the interworking of heterogeneous wireless local area networks (WLANs) and mobile (cellular) networks. This topic has been under research for sometime, but cannot be solved quickly and easily due to the core differences in the inherent philosophy and technology between WLANs and mobile (wide area) networks. Although both categories of wireless networking technologies have been thoroughly standardized, with new versions continuously under development, no single comprehensive interworking standard has yet been fully endorsed.
The technology principles form only one set of issues that need to be resolved for the effective use of a selected available network. Other issues include the best network in terms of rate, quality of service (QoS), and price; proper, smooth, quick, and safe handover; and smart accounting. The other issues are represented by the problem of potentially different owners of WLANs (hotspots) and mobile networks, and the different approaches by various operators to manage users and network use. With more and more mobile operators also running hotspots, these issues could be solved more easily, though possibly behind the scenes.
This book includes five chapters. The first chapter very briefly reviews research issues involving WLAN-universal mobile telecommunications system (UMTS) interworking and system modeling. The next three core chapters provide insight into the three interworking technology schemes for the cellular/WLAN integrated network. The authors present “an in-depth analysis of a simple WLAN-first resource allocation scheme,” where WLAN is always preferred over a mobile network whenever possible. Second, they review call admission with randomized selection and distributed admission control. Third, they discuss a size-based load-sharing scheme that enhances QoS provisioning through access selection and scheduling.
The selected schemes are only some of many, and they are presented from the perspective of research rather than implementation. In other words, the schemes are based on theoretical analysis and simulation validation to provide numerical results supported by mathematical functions and charts. The final page of the book lists a number of research problems that remain to be sorted out, including video streaming support and interworking in a vehicular environment. The brief concludes with a list of 62 references (without any links) from the 1970s through 2011.
The book requires the reader to have a solid knowledge of both WLAN and mobile network principles. The readers who are most likely to benefit from it are not wireless professionals, implementers, or network developers, but rather research specialists and graduate students interested in the topic. This is the major drawback of the whole “SpringerBriefs in Computer Science” series. Although quite timely, the briefs cover a range of content from professional to academic, and thus are not oriented to a specific category of readers. The individual volumes do not even attempt to identify intended readers.