Abstract
The growing demands of radio spectrum urgently require more efficient and effective spectrum exploitation and management technologies. Cognitive radio technology and its networking not only explores the potential white spectrum resources temporally and geographically, but also enables an extensive efficient utilization and optimization of the current allocated spectrum resources. Therefore, rapid progress has been made in the research on cognitive radio and its networking technologies to facilitate more flexibilities in spectrum utilization and management. In this chapter, the authors first summarize the current various advanced and flexible spectrum management schemes, including spectrum trading, leasing, pricing, and harvesting, and analyze their advantages and disadvantages. Then, they take the viewpoints of both the spectrum marketing perspective and spectrum technical perspective, and they propose the centralized and distributed dynamic spectrum sharing schemes, respectively. In particular, the authors introduce many novel advanced spectrum sharing scheme and summarize the open and possible research problems.
TopBasics Of Cognitive Radio And Spectrum Management
The rapid growth in wireless services over the past decade has illuminated the growing demands for radio spectrum, and we know the potentially-rich spectrum resource is limited, valuable and increasingly congested. Current traffic and high user experience quality, which also challenges the current spectrum management and allocation schemes allover the world. According to Cisco Visual Networking Index (VNI), mobile video traffic is already over 50 percent of mobile data traffic, and is expected to account for 66 percent of global mobile data demand by 2017. In addition, the global mobile data traffic grew 70 percent in 2012 with strongest growth in countries such as Japan and Korea where 4G penetration is high. According to this Cisco report, the global mobile data traffic is expected to grow steadily at CAGR of 66 percent from 2012 to 2017, which means a 13-fold increase over 2012 and over 11.2 exabytes per month by the end of 2017 (4G Americas, 2013).
All the information and traffic growth predictions are showing demand for data that could overwhelm the wireless network resources due to finite and limited spectrum availability even though technology evolution is improving the efficiency and capacity of the wireless networks. To be ready to accommodate the growth, the wireless industry needs additional spectrum and associated policy innovation.
On the other hand, recent spectrum measurement campaigns indicate that most of the licensed spectrum has been under-utilized. Even in the most crowded area near downtown Washington, DC, where both government and commercial spectrum use is intensive, only 38% of the licensed spectrum remains occupied and the rest of spectrum resource, white space/spectrum hole is wasted. These statistics and studies spur the FCC to open up licensed spectrum bands and pursue new innovative technologies to encourage dynamic use of the under-utilized spectrum (Mitola & Maguire,1999).
On the ITU 5D working group meeting in October 2012, some countries and organizations proposed the IMT system frequency demand situation in 2015 and 2020, as shown in the Table 1, in 2020, all countries have larger demand of frequency(ITU, 2013).
Table 1.
The IMT system frequency demand situation in 2015 and 2020(ITU, 2013)
| The United States | Need to add 175 MHz by 2015 |
| Australia | Need to add 300 MHz by 2020 |
| Russia | Need to add 385 MHz by 2020 |
| Japan | Total demand is 2020 MHZ by 2020 |
| Huawei, Ericsson, Nokia | Total demand is 1880 MHZ by 2020 |
| GSMA | Total demand is 1600 to 1800 MHZ by 2020 |
| India | Need to add 500 MHz by 2020 |
Key Terms in this Chapter
Cognitive Radio Networks: In which a set of primary users make opportunistic spectrum access to support cognitive radios within their coverage areas.
Spectrum Trading: The Radio Spectrum Policy Group Opinion on Secondary Trading of Rights to use Radio Spectrum.
Global System for Mobile Communication, GSM: Is an international standard.
Spectrum Overlay: A spectrum management principle whereby a secondary user uses a channel from a primary user only when it is not occupied.
Spectrum Mobility: Process by which a cognitive-radio user changes its frequency of operation. Cognitive-radio networks aim to use the spectrum in a dynamic manner by allowing radio terminals to operate in the best available frequency band, maintaining seamless communication requirements during transitions to better spectrum.
Spectrum Sharing: Through wireless scene perception spectrum hole detection, according to the result of perception to adjust each transmitter power output, then with appropriate strategy to select the most appropriate frequency modulation coding for reliable communication, realize the cognitive users and authorized users, and the cognitive spectrum sharing between the cognitive users.
Quality of Experience, QoE: Is a measure of a customer's experiences with a service (web browsing, phone call, TV broadcast, call to a Call Center).
Interference Management: Any scheme to release, mitigate, use and control the interference, interference cancellation/mitigation/avoidance/alignment.
Spectrum Leasing: Part of the FCC’s secondary market initiatives designed to remove regulatory barriers and increase access to spectrum.
Compound Average Growth Rate, CAGR: The annual growth rate of a specific period of time.
Spectrum Market: A basic policy choice is whether to define and enforce spectrum, property rights, which can be traded.
Secondary Service Provider, SSP: To harvest the available spectrum bands and facilitate the accessing of secondary users without cognitive radio capability.
Energy Management: Dynamic adjustment of energy to save energy according to the channel state information or the traffic situations.
Cognitive Radio: A radio can provide abundant new spectrum opportunities by exploiting underutilized or underutilized spectrum, temporarily and geographically.
Federal Communications Commission, FCC: An independent federal government agency, authorized by the statute for the time being in the us congress, and led by the congress.
Wi-Fi: Is a way to personal computers, handheld devices (such as PDA, mobile phones) and other terminals connected to each other wireless technology.
Long Term Evolution, LTE: Is a standard for wireless communication of high-speed data for mobile phones and data terminals. It is based on the GSM/EDGE and UMTS/HSPA network technologies, increasing the capacity and speed using a different radio interface together with core network improvements.
General Packet Radio Service, GPRS: A packet-switching technology that enables data transfers through cellular networks. It is used for mobile internet, MMS and other data communications.
Spectrum Congestion: The situation that occurs when many stations transmit simultaneously using frequencies that are close together.
Licensed Spectrum: Allocated by auction and traded in secondary markets, relative to how much will utilize bands in which open wireless systems are permitted.
Resource Management: Is the efficient and effective deployment of a node's resources when they are needed.
Remote Radio Heads (RRHs): Have become one of the most important subsystems of today's new distributed base stations. The remote radio head contains the base station's RF circuitry plus analog-to-digital/digital-to-analog converters and up/down converters.
Spectrum Pricing: a range of spectrum management activities and tools including administrative fees, spectrum usage and spectrum prices determined by way of Government Policy and market mechanisms.
Nash Equilibrium: A solution concept of a non-cooperative game involving two or more players, in which each player is assumed to know the equilibrium strategies of the other players, and no player has anything to gain by changing only their own strategy.
Power Control: Is the intelligent selection of transmit power in a communication system to achieve good performance within the system, which can improve the capacity of network and prolong the battery of mobile site.