A survey of cognitive radio and TV white spaces in Malaysia

Abstract

Cognitive radio (CR) enables spectrum sharing by allowing new unlicensed services from secondary users to operate in pre-allocated bands in an opportunistic manner. TV white space (TVWS) is a portion of the spectrum in ultra-high frequency (UHF) and very-high frequency bands, which is not utilised by primary users in specific time and location. It is envisaged that more spectrum will be available after digital switchover (DSO) TV transmission replaces the current analogue system. Recently, the regulators in the USA and in the UK have given approval for companies to operate new communication systems with the capability of utilising TVWS spectrum. This paper provides a comprehensive overview of the CR technology and quantifies the TVWS status in Malaysia to expose the spectrum reuse opportunities for future secondary user deployment. Taking the 18 major cities in Malaysia into consideration, we find that all seven TV stations utilise from two to seven of the UHF channels. In our analysis, three usage scenarios were considered, where the utilisation of the 40 UHF channels is full, half and a third. For each case, it was discovered that TVWS was 82.5%, 65% and 46.1%, which can be opportunistically utilised by CR users.

An intelligent approach for resource allocation in the cognitive radio vehicular ad hoc network

“…whereĤ avm =Ĥ m( T s )+Ĥm(T) 2 . The EE is defined as the ratio of the average system throughput to the average power consumption, which is given by…”

“…Traditional fixed frequency allocation policy necessitates more spectral resources to resolve the spectrum congestion problem. Hence, cognitive radio (CR) is introduced as a promising technology that uses the available spectral resources in an efficient manner . The concept of CR has been applied in various wireless technologies such as in disaster response networks, tactical networks, smart grid, etc.…”

“…Hence, cognitive radio (CR) is introduced as a promising technology that uses the available spectral resources in an efficient manner. 1,2 The concept of CR has been applied in various wireless technologies such as in disaster response networks, 3 tactical networks, 4 smart grid, 5 etc. Because of exponential increase in the vehicular devices, the CR technology is deployed in vehicular communications to exploit the available spectrum among the vehicular secondary users (VSUs) in CR vehicular ad hoc network (CR-VANET).…”

QoS optimization‐based dynamic secondary spectrum access model

“…Cognitive radio (CR) technology offers a solution to the spectrum scarcity issues using the dynamic spectrum access . Research claims that the radio spectrum resource is heavily underutilized due to the static allocation and on an average, almost 70% of it is being wasted . The CR proposes to improve the spectrum utilization efficiency through its opportunistic access in the underutilized portions that exist as whitespaces in the already allocated spectrum.…”

Joint Channel Assignment and Power Allocation Based on Maximum Concurrent Multicommodity Flow in Cognitive Radio Networks

“…It consists of Ultrahigh Frequency/ Very High Frequency (UHF/VHF) that are either freed via the digital switch over process or unused due to local regulations [4]. Therefore, FCC considered that the traditional fixed spectrum assignment policy has to be palliated.…”