Spatial capacity
Encyclopedia
Spatial capacity is an indicator of "data
intensity" in a transmission
medium. It is usually used in conjunction with wireless transport mechanisms. This is analogous to the way that lumens
per square meter determine illumination intensity.
Spatial capacity focuses not only on bit
rates for data transfer but on bit rates available in confined spaces defined by short transmission ranges. It is measured in bits per second per square meter.
Among those leading research in spatial capacity are Jan Rabaey at the University of California, Berkeley
. Some have suggested the term "spatial efficiency" as more descriptive. Marc Weiser, former chief technologist of Xerox PARC
was another contributor to the field who commented on the importance of spatial capacity.
The System spectral efficiency is the spatial capacity divided by the bandwidth in hertz of the available frequency band.
Data
The term data refers to qualitative or quantitative attributes of a variable or set of variables. Data are typically the results of measurements and can be the basis of graphs, images, or observations of a set of variables. Data are often viewed as the lowest level of abstraction from which...
intensity" in a transmission
Data transmission
Data transmission, digital transmission, or digital communications is the physical transfer of data over a point-to-point or point-to-multipoint communication channel. Examples of such channels are copper wires, optical fibres, wireless communication channels, and storage media...
medium. It is usually used in conjunction with wireless transport mechanisms. This is analogous to the way that lumens
Lumen (unit)
The lumen is the SI derived unit of luminous flux, a measure of the total "amount" of visible light emitted by a source. Luminous flux differs from power in that luminous flux measurements reflect the varying sensitivity of the human eye to different wavelengths of light, while radiant flux...
per square meter determine illumination intensity.
Spatial capacity focuses not only on bit
Bit
A bit is the basic unit of information in computing and telecommunications; it is the amount of information stored by a digital device or other physical system that exists in one of two possible distinct states...
rates for data transfer but on bit rates available in confined spaces defined by short transmission ranges. It is measured in bits per second per square meter.
Among those leading research in spatial capacity are Jan Rabaey at the University of California, Berkeley
University of California, Berkeley
The University of California, Berkeley , is a teaching and research university established in 1868 and located in Berkeley, California, USA...
. Some have suggested the term "spatial efficiency" as more descriptive. Marc Weiser, former chief technologist of Xerox PARC
Xerox PARC
PARC , formerly Xerox PARC, is a research and co-development company in Palo Alto, California, with a distinguished reputation for its contributions to information technology and hardware systems....
was another contributor to the field who commented on the importance of spatial capacity.
The System spectral efficiency is the spatial capacity divided by the bandwidth in hertz of the available frequency band.
Relative spatial capacities
Engineers at Intel and elsewhere have reported the relative spatial capacities of various wireless technologies as follows:- IEEE 802.11b 1,000 (bit/s)/m²
- BluetoothBluetoothBluetooth is a proprietary open wireless technology standard for exchanging data over short distances from fixed and mobile devices, creating personal area networks with high levels of security...
30,000 (bit/s)/m² - IEEE 802.11a 83,000 (bit/s)/m²
- Ultra-widebandUltra-widebandUltra-wideband is a radio technology that can be used at very low energy levels for short-range high-bandwidth communications by using a large portion of the radio spectrum. UWB has traditional applications in non-cooperative radar imaging...
1,000,000 (bit/s)/m² - IEEE 802.11g N/A