The neXt Generation program or XG is a technology development project sponsored by DARPA's Strategic Technology Office, with the goals to "develop both the enabling technologies and system concepts to dynamically redistribute allocated spectrum along with novel waveforms in order to provide dramatic improvements in assured military communications in support of a full range of worldwide deployments." [1] It is financed by the United States government within the aim of developing a de facto standard for cognitive radio and dynamic spectrum regulation. [2]
Particularly, XG is focused on the development of dynamic spectrum access (DSA) demonstration and capability as well as the evaluation of three fundamental principles, namely: the principle of "Do No Harm"; "Add Value" principle; and, DSA devices development that provide equivalent reliability and service. [3] The first principle involves the design of DSA radios in a way that does not interfere with viable links while the second maintains that DSA radios offer positive benefit after all the overhead costs and resources are considered. [3] In the Wireless World Research Forum of 27 October 2003, Preston Marshall, program manager of DARPA XG Program, said "The primary product of the XG program is not a new radio, but a set of advanced technologies for dynamic spectrum access." [4]
From 2006 to 2008, DARPA held numerous XG program demonstrations such as the experiment that involved the deployment of a field of conventionally deconflicted wireless links that included typical military, public safety, and civilian point-to-point links, covering several kilometers. [3] In 2006, an XG technology was deployed in a field trial and demonstrated a robust networking capability amid challenging mobile scenarios. [5] The program is also engaged in the development of architectural framework, protocol design, and building prototypes for DSA networks. [5] One of its notable projects is the One Shot XG system, which is being developed to improve the accuracy of military snipers by calculating variables such as crosswind condition, maximum effective range of the weapon, and weapon alignment. [6]
A wireless network is a computer network that uses wireless data connections between network nodes.
Software-defined radio (SDR) is a radio communication system where components that have been traditionally implemented in hardware are instead implemented by means of software on a personal computer or embedded system. While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics render practical many processes which were once only theoretically possible.
In telecommunications and computer networks, a channel access method or multiple access method allows more than two terminals connected to the same transmission medium to transmit over it and to share its capacity. Examples of shared physical media are wireless networks, bus networks, ring networks and point-to-point links operating in half-duplex mode.
Wireless local loop (WLL), is the use of a wireless communications link as the "last mile / first mile" connection for delivering plain old telephone service (POTS) or Internet access to telecommunications customers. Various types of WLL systems and technologies exist.
WiMAX is a family of wireless broadband communication standards based on the IEEE 802.16 set of standards, which provide multiple physical layer (PHY) and Media Access Control (MAC) options.
4G is the fourth generation of broadband cellular network technology, succeeding 3G. A 4G system must provide capabilities defined by ITU in IMT Advanced. Potential and current applications include amended mobile web access, IP telephony, gaming services, high-definition mobile TV, video conferencing, and 3D television.
A mesh network is a local network topology in which the infrastructure nodes connect directly, dynamically and non-hierarchically to as many other nodes as possible and cooperate with one another to efficiently route data from/to clients. This lack of dependency on one node allows for every node to participate in the relay of information. Mesh networks dynamically self-organize and self-configure, which can reduce installation overhead. The ability to self-configure enables dynamic distribution of workloads, particularly in the event a few nodes should fail. This in turn contributes to fault-tolerance and reduced maintenance costs.
A cognitive radio (CR) is a radio that can be programmed and configured dynamically to use the best wireless channels in its vicinity to avoid user interference and congestion. Such a radio automatically detects available channels in wireless spectrum, then accordingly changes its transmission or reception parameters to allow more concurrent wireless communications in a given spectrum band at one location. This process is a form of dynamic spectrum management.
IEEE 802.22, is a standard for wireless regional area network (WRAN) using white spaces in the television (TV) frequency spectrum. The development of the IEEE 802.22 WRAN standard is aimed at using cognitive radio (CR) techniques to allow sharing of geographically unused spectrum allocated to the television broadcast service, on a non-interfering basis, to bring broadband access to hard-to-reach, low population density areas, typical of rural environments, and is therefore timely and has the potential for a wide applicability worldwide. It is the first worldwide effort to define a standardized air interface based on CR techniques for the opportunistic use of TV bands on a non-interfering basis.
Reconfigurability denotes the Reconfigurable Computing capability of a system, so that its behavior can be changed by reconfiguration, i. e. by loading different configware code. This static reconfigurability distinguishes between reconfiguration time and run time. Dynamic reconfigurability denotes the capability of a dynamically reconfigurable system that can dynamically change its behavior during run time, usually in response to dynamic changes in its environment.
Orthogonal frequency-division multiple access (OFDMA) is a multi-user version of the popular orthogonal frequency-division multiplexing (OFDM) digital modulation scheme. Multiple access is achieved in OFDMA by assigning subsets of subcarriers to individual users. This allows simultaneous low-data-rate transmission from several users.
Spectrum management is the process of regulating the use of radio frequencies to promote efficient use and gain a net social benefit. The term radio spectrum typically refers to the full frequency range from 3 kHz to 300 GHz that may be used for wireless communication. Increasing demand for services such as mobile telephones and many others has required changes in the philosophy of spectrum management. Demand for wireless broadband has soared due to technological innovation, such as 3G and 4G mobile services, and the rapid expansion of wireless internet services.
A wireless ad hoc network (WANET) or Mobile ad hoc network (MANET) is a decentralized type of wireless network. The network is ad hoc because it does not rely on a pre-existing infrastructure, such as routers in wired networks or access points in managed (infrastructure) wireless networks. Instead, each node participates in routing by forwarding data for other nodes, so the determination of which nodes forward data is made dynamically on the basis of network connectivity and the routing algorithm in use.
Radio resource management (RRM) is the system level management of co-channel interference, radio resources, and other radio transmission characteristics in wireless communication systems, for example cellular networks, wireless local area networks, wireless sensor systems, and radio broadcasting networks. RRM involves strategies and algorithms for controlling parameters such as transmit power, user allocation, beamforming, data rates, handover criteria, modulation scheme, error coding scheme, etc. The objective is to utilize the limited radio-frequency spectrum resources and radio network infrastructure as efficiently as possible.
The IEEE Communications Society (ComSoc) promotes the advancement of science, technology and applications in communications and related disciplines. It fosters presentation and exchange of information among its members and the technical community throughout the world. The Society maintains a high standard of professionalism and technical competency. The IEEE Communications Society is a professional society of the IEEE.
In communication networks, cognitive network (CN) is a new type of data network that makes use of cutting edge technology from several research areas to solve some problems current networks are faced with. Cognitive network is different from cognitive radio (CR) as it covers all the layers of the OSI model.
The Dynamic Spectrum Access Networks Standards Committee (DySPAN-SC), formerly Standards Coordinating Committee 41 (SCC41), and even earlier the IEEE P1900 Standards Committee, is sponsored by the Institute of Electrical and Electronics Engineers (IEEE). The group develops standards for radio and spectrum management. Its working groups and resulting standards, numbered in the 1900 range, are sometimes referred to as IEEE 1900.X.
Established in 1996, the Wireless Innovation Forum is a non-profit "mutual benefit corporation" dedicated to advocating for spectrum innovation and advancing radio technologies that support essential or critical communications worldwide. Forum members bring a broad base of experience in Software Defined Radio, Cognitive Radio and Dynamic Spectrum Access technologies in diverse markets and at all levels of the wireless value chain to address emerging wireless communications requirements. The forum acts as a venue for its members to collaborate to achieve these objectives.
Opportunistic mesh (OPM) is a wireless networking technology that aims to provide reliable and cost-effective wireless bandwidth when used to build the networking infrastructure of large-scale wireless systems.
IEEE 802.11af, also referred to as White-Fi and Super Wi-Fi, is a wireless computer networking standard in the 802.11 family, that allows wireless local area network (WLAN) operation in TV white space spectrum in the VHF and UHF bands between 54 and 790 MHz. The standard was approved in February 2014. Cognitive radio technology is used to transmit on unused portions of TV channel band allocations, with the standard taking measures to limit interference for primary users, such as analog TV, digital TV, and wireless microphones.
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