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In this paper, we present the world’s first prototype of the IEEE 802.11af-based baseband (BB) integrated circuit (IC) enabling compact, low power consumption and even low cost TV white-space (TVWS) devices. Although it has been already over three years since the IEEE 802.11af was standardized in December 2013 as a wireless local area network (WLAN) system utilizing the TVWS, the IEEE 802.11af-based...
Since the FCC stated a policy on unlicensed use of the TV white-spaces (TVWS) in November 2008, a number of countries and regions have studied utilization of the TVWS, and some communication systems using the TVWS have been globally discussed and standardized. It has been three years since the IEEE 802.11af has been standardized, while the IEEE 802.11af-based system is not yet applied for commercial...
In recent years, there has been an increasing number of Software Defined Wireless Access Network (SDWAN) proposals aiming to cope with the proliferation of mobile devices, as well as, the novel Quality of Service (QoS) demands. One of the most important issues in the SDWANs is to maintain a scalable and robust OpenFlow channel through which the network control and update information (i.e., OpenFlow...
An IEEE 802.11af indoor trial experiment has been conducted in the Ofcom pilot program of the United Kingdom. This paper describes an indoor propagation characterization and throughput estimation method using prototype devices based on the IEEE 802.11af standard. Since the IEEE 802.11af is recent technology for TV white space (TVWS) spectrum sharing, indoor propagation measurements at TVWS band for...
Utilization of the TV white-spaces (TVWS), which are spatially or temporally unused frequency in TV bands, is promising technology to alleviate spectrum resource shortage. Services using the TVWS have been already started in the U.S.A., and the TVWS pilot program has been performed and test operation of qualified white-spaces database (WSDB) has been started by the Ofcom in the U.K. Authors have developed...
This paper performs the world's first IEEE 802.11af based Wireless Local Area Networks (WLAN) operating in TV White Space (TVWS) indoor experiment in the Ofcom TVWS pilot program of the UK. The prototype system consists of TVWS Database (WSDB), Registered Location Secure Server (RLSS), and two prototype hardware for an Access Point (AP) and a Station (STA). The developed WSDB qualified by Ofcom TVWS...
This paper summarizes research and development results regarding white space (WS) communication systems. A fundamental configuration and IEEE standardization regarding WS communication systems are introduced and then our developed TV WS database (WSDB) and TV WS devices (WSD) are introduced.
Since TV white space systems must not cause interference to TV broadcasting performance, a propagation model for the interference estimation is very important. In this paper, a propagation experiment has been conducted using a TV white space station to develop a propagation model which estimates the maximum received power for interference evaluations. From received power measurements within several...
For the coexistence management between primary and secondary users in TV white space, a simple propagation model for short range transmission and low antenna height is needed to define the interference risk area to primary user from secondary user. For estimating the area, measurements of building penetration loss have been conducted at UHF band, and a propagation model based on free space loss with...
The Wi-Fi technology has been fast growing and available on a huge number of electronic devices. Moreover, due to the easiness in deployment a Wi-Fi user is normally in the coverage of several surrounding Wi-Fi access points (APs). The Wi-Fi virtualization, which abstracts a Wi-Fi interface to appear as several virtual ones to the user, is one of the most significant current approaches in improving...
A field experiment of TV White Space (TVWS) communications was conducted using developed systems following IEEE 802.22 and IEEE 802.11af standards and succeeded to have the world first throughput, distance, and application testing. The IEEE 802.22 system achieved throughput of 4.5 Mbps for uplink and 5.2 Mbps for downlink over 12.7 km. Also, feasibility of applications such as web browsing, video...
Recently, a spectrum resource shortage problem has been aggravated in a cellular system due to growth of service or application business based on high-speed and high-capacity communication. To solve this problem, data traffic offloading to “white-spaces” has been promoted worldwide. In particular, white-spaces in the TV band (TVWS, TV White-spaces) has attracted attentions for securing more channels...
Cognitive Wireless Router (CWR) system developed by NICT using the cognitive radio technologies were deployed in the disaster area of the great earthquake hit east of Japan in March 11, 2011. Totally 68 units of the CWR were deployed in evacuation sites, volunteer centers, hospitals, disaster headquarters, temporary housings, and so on. The system was operated for 2 years according to strong requests...
A wireless communication system in TV broadcasting band (470MHz–710MHz) has been developed. In the system its operational channels are set to the radio equipment according to calculation results provided from the white space database (WSDB). By the system, efficient wireless communication environment to accommodate increasing mobile traffic is expected, which consequently loads off traffic of wireless...
AMPHIBIA is a framework which enables dynamic virtual network provisioning over wired and wireless networks for providing diverse services by coordinated reconfiguration in both sides of wired and wireless networks, exploiting the emerging network virtualization and cognitive radio technologies. AMPHIBIA introduces a new concept of a virtual cognitive base station (vCBS), a cognitive base station...
This paper shows autonomous optimization techniques for distributed cognitive radio architecture. Based on the context information exchange mechanism standardized in IEEE1900.4, we assume that the terminals can obtain various types of context information of radio access networks (RANs) and they can make optimal decisions by themselves using the shared information. In our research, we apply the neural...
Realization of wireless communications in TV white space is one of the most urgent research and development issues to accommodate rapidly increasing mobile traffic. In order to ensure avoidance of interference from secondary systems to primary systems, adoption of White Space Database (WSDB) is the most practical and reliable strategy. This paper proposes a white space network system that determines...
This paper investigates effectiveness of distributed radio access network (RAN) selection schemes to optimize radio resource usage, for the realistic heterogeneous wireless networks, in which the distribution of the base stations are non-uniform and the non-cognitive legacy terminals also connect to the same RANs. Our proposed algorithm is based on mutually-connected and higher-order neural networks,...
To cope with the increasingly diversifying services, QoS, and network architectures, network virtualization is a promising technology that enables the concurrent deployment of multiple network technologies on a shared network. However, traditional research on network virtualization preliminarily focuses on a wired environment and network virtualization for a wireless environment is not well studied...
The current radio environment is characterized by its heterogeneity. Different aspects of this heterogeneity include: multiple operators and services, various radio access technologies, different network topologies, broad range of radio equipment, and multiple frequency bands. Such environment has a lot of technical and business opportunities. The examples are: joint management of several radio access...
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