Future Internet_**2010**, \(2\), 212-237; doi:10.3390/fi2030212  
_future internet_  
**ISSN 1999-5903**  
www.mdpi.com/journal/futureinternet  
_Review_  
**Misbehavior Scenarios in Cognitive Radio Networks**  
**[PERSON] 1, [PERSON] 1, [PERSON] 1, [PERSON] 2, [PERSON] 3, [PERSON] 3, [PERSON] 2 and [PERSON] 1**  
multimode protocol stacks, the new generation smart-phones will support fast wireless system discovery and selection, and functions that determine and update the location of the terminals in various systems. This will provide the necessary flexibility to perform horizontal, as well as vertical, handoffs, with minimum handover latency and packet loss. Thus, network heterogeneity will enable the ubiquitous network paradigm [3]. Additionally, they enable the self-organization of personal area networks where many, different personal devices, handsets, as well as sensors and actuators, in the environment will be discovered, associated, and interact easily within dynamically assembled sets of surroundings. Today's Bluetooth-based paradigm of personal area networking will be extended to a more dynamic environment where, for example, as a user changes context and surroundings, different audio-video devices will be selected for rendering, enabling personal mobility [2]. Moreover, wireless solutions are more easily introduced or updated in everyday life, including increasing data rates and performance (even though the technical problems are typically much harder for wireless communications). Furthermore, a plethora of devices of small form factor, equipped with wireless communications capabilities, will also be the building blocks of the _Internet of Things_[4, 5]. This new ubiquitous (mostly machine-to-machine) communications environment will challenge all current networking layers. Focusing on the wireless communications layer, one of the most significant challenges is how to cope with the increased demand for spectrum that the vast amount of wireless devices will bring about. Also, with sensor networks being an integral part of a future wireless Internet, specific challenges emerge [6]. Crowded spectrum may lead to excessive packet loss for traffic that is inherently bursty (due to the event-driven traffic patterns in wireless sensor networks), and retransmissions will faster exhaust the limited power resources of sensor nodes. Also, in many cases, reliably communicating sensor readings is critical (e.g., for healthcare applications). Cognitive Radio networks are part of the answer. Recent advances in the area of wireless communications promise a breakthrough both from the user and the service provider point of view. There is a clear trend towards open (or at least more open) wireless access, mainly driven by the low cost and the ease of deployment of equipment that operates in unlicensed (more accurately, \"license exempt\") spectrum bands. On the other hand, there is the realization that spectrum is often scarce (e.g., in the case of unlicensed bands in dense urban environments), or underutilized (e.g., in the case of analog TV bands). On the other hand, acquiring a license to operate in a contention-free fashion is very costly (see, for instance, the 3G spectrum auctions). The above observations have, to a significant extent, motivated research in the areas of self-organized wireless systems and Cognitive Radio (CR) networks [7]. Typical CR networking scenarios involve a number of secondary (unlicensed) users sharing spectrum determined not in use at the time by the primary (licensed) users. The exact meaning of this sentence and many of its terms continues to be the subject of intense research and various proposals. This research is also backed up by the emergence of Software-Defined Radio (SDR) technologies and the fact that, with the advent of open-source device drivers for Wi-Fi cards, many additional configuration options are now available. Moreover, tweaking protocol operation to achieve performance optimization is now sometimes possible.