White Space Standards
A series of standards have been created to support White Space development. Information about each of these can be found in the links below.
ECMA-392: MAC and PHY for Operation in TVWS
This Standard specifies a medium access control (MAC) sub-layer and a physical (PHY) layer for personal/portable cognitive wireless networks operating in TV bands. This Standard also specifies a MUX sublayer for higher layer protocols.
This Standard specifies a number of incumbent protection mechanisms which may be used to meet regulatory requirements, which themselves are outside of the scope of this standard. Conforming devices implement the MUX sub-layer, MAC sub-layer and the PHY layer as specified herein and support at least one of the device types (master, peer, or slave) and at least one of bandwidths (6 MHz, 7 MHz, 8 MHz), and may support multiple antennae modes.
IEEE 1900.4a: Standard for Architectural Building Blocks Enabling Network-Device Distributed Decision Making for Optimized Radio Resource Usage in Heterogeneous Wireless Access Networks
Additional components of the IEEE 1900.4 system are defined in this amendment to enable mobile wireless access service in white space frequency bands without any limitation on used radio interface (physical and media access control layers, carrier frequency, etc.).
1900.4a uses the existing IEEE standard 1900.4 as a basis, and defines additional interfaces and entities to add efficient operation of white space wireless systems.
IEEE 802.11af: IEEE Standard for Information Technology – Telecommunications and Information Exchange Between Systems – Local and Metropolitan Area Networks – Specific Requirements – Part 11
The TGaf defines a white space map (WSM) describing available channels and their respective maximum transmit power allowed. This WSM will be issued by an enabling station towards dependent stations by any available means (including wired and wireless communication methods). The WSM currently is optional.
Enabling stations are allowed to enable dependent stations for operation in the TV white space (TVWS). Enabling stations must have TV database access and must know their position. They grant access to certain channels. Dependent stations must, after being enabled, perform sensing for a certain period of time before they are allowed to access the channel. Dependent stations are not mandated to know their geographical position (which is inconsistent, regarding the fact that enabling stations may be set apart). Procedures and timing have been defined.
The standard will explicitly allow and make use of multi-channel operations. That is, TGaf systems may operate simultaneously in ISM bands and TVWS. Enabling and beaconing may be performed in the ISM band, data communications may take place in the TVWS (which complicates sensing of TGaf access points by concurrent TVWS users).
The standard will support 5, 10, 20 and 40 MHz bandwidth in the TVWS (set by the enabling station according to TVWS availability). Allowance for 2.5 MHz bandwidth operation is currently under discussion.
IEEE 802.15.4m: IEEE Standard for Information Technology – Telecommunications and Information Exchange Between Systems – Local and Metropolitan Area Networks – Specific Requirements – Part 15.4
This amendment specifies a physical layer for 802.15.4 meeting TV white space regulatory requirements and also any necessary MAC changes needed to support this physical layer. The amendment enables operation in the available TV white space, supporting typical data rates in the 40 kbits per second to 2000 kbits per second range, to realize optimal and power efficient device command and control applications. It supports accepted methods of TV White Space coexistence in existence at the time of development.
IEEE 802.22-2011: Cognitive Wireless RAN Medium Access Control (MAC) and Physical Layer (PHY) specifications: Policies and procedures for operation in the TV Bands
The development of the IEEE 802.22 Wireless Rural Access Network (WRAN) standard is targeted at using a CR approach to allow sharing areas of television broadcast service spectrum that are unused. These areas of spectrum will be allocated based on geographical location and can only be used on a non-interfering basis. The aim of this standard is to bring broadband access to rural environments which are hard to reach using traditional broadband technologies.
Other incumbent broadcasts could be in operation within the designated TV White Space (TVWS) bands (i.e. Digital and Analogue TV broadcasting and low-powered wireless microphones) and the 802.22 WRANs are designed to operate with no harmful interference to them.
IEEE P802.19.1: Standard for Information Technology – Telecommunications and Information Exchange Between Systems – Local and Metropolitan Area Networks – Specific Requirements – Part 19: TV White Space Coexistance Methods
When complete the standard will provide services and methods to allow the coexistence of various cognitive radio systems in TVWS frequency bands. Two of the main services that are provided by the standard will be:
Discovery Service – Allows white space radio systems to discover neighbouring white space radio systems with which they will need to coexist. In response to a request from a white space radio system, the 802.19.1 coexistence system will provide information on the neighbouring systems and the channels that are currently in use.
White Space Management Service – Helps white space radio systems to select an operating channel among the available channels that are indicated by a TVWS database. This service can also provide a transmission schedule for the selected operating channel if there is a need to share one channel amongst several white space radio systems. This is required to provide fair spectrum access for different white space systems.