A wide variety of different wireless data technologies exist, some in direct
competition with one another, others designed for specific applications.
Wireless technologies can be evaluated by a variety of different metrics of
which some are described in this entry. Standards can be grouped as follows in
increasing range order: Personal Area Network systems are
intended for short range communication between devices typically controlled by
a single person. Some examples include wireless headsets for mobile phones or
wireless heart rate sensors communicating with a wrist watch. Some
of these technologies include standards such as ANT UWB, Bluetooth, ZigBee, and
Wireless USB. Wireless Sensor Networks are,
generically, networks of low-power, low-cost devices that interconnect
wirelessly to collect, exchange, and sometimes act-on data collected from
their physical environments - "sensor networks". Nodes typically connect in a
star or mesh topology. While most individual nodes in a WSAN are expected
to have limited range, particular nodes may be capable of more expansive
communications and any individual WSAN can span a wide geographical range. An
example of a WSAN would be a collection of sensors arranged throughout an
agricultural facility to monitor soil moisture levels, report the data back to
a computer in the main office for analysis and trend modeling, and maybe
turn on automatic watering spigots if the level is too low.
For wider area communications, Wireless Local Area Network is used. WLANs are
often known by their commercial product name Wi-Fi. These systems are used to
provide wireless access to other systems on the local network such as other
computers, shared printers, and other such devices or even the internet.
Typically a WLAN offers much better speeds and delays within the local
network than an average consumer's Internet access. Older systems that
provide WLAN functionality include DECT and HIPERLAN. These however are no
longer in widespread use. One typical characteristic of WLANs is that they are
mostly very local, without the capability of seamless movement from one
network to another. Cellular networks or WAN are designed
for city-wideglobal coverage areas and seamless mobility from one access point
to another allowing seamless coverage for very wide areas. Cellular network
technologies are often split into 2nd generation 2G, 3G and 4G networks.
Originally 2G networks were voice centric or even voice only digital
cellular systems. Typical 2G standards include GSM and IS-95 with extensions
via GPRS, EDGE and 1xRTT, providing Internet access to users of originally
voice centric 2G networks. Both EDGE and 1xRTT are 3G standards, as defined by
the ITU, but are usually marketed as 2.9G due to their comparatively low
speeds and high delays when compared to true 3G technologies.
True 3G systems such as EV-DO, W-CDMA provide combined circuit switched and
packet switched data and voice services from the outset, usually at far better
data rates than 2G networks with their extensions. All of these services can be
used to provide combined mobile voice access and Internet access at remote
locations. 4G networks provide even higher bitrates
and many architectural improvements, which are not necessarily visible to the
consumer. The current 4G systems that are deployed widely are HSPA+, WIMAX and
LTE. The latter two are pure packet based networks without traditional voice
circuit capabilities. These networks provide voice services via VoIP.
Some systems are designed for point-to-point line-of-sight
communications, once two such nodes get too far apart they can no longer
communicate. Other systems are designed to form a wireless mesh network using
one of a variety of routing protocols. In a mesh network, when nodes get too
far apart to communicate directly, they can still communicate indirectly through
intermediate nodes. Standards
The following standards are included in this comparison.
= Wireless Wide Area Network= EDGE
EV-DO x1 Rev 0, Rev A, Rev B and x3 standards.
Flash-OFDM: FLASH(Fast Low-latency Access with Seamless Handoff)-OFDM
GPRS HSPA D and U standards.
Lorawan LTE
RTT UMTS over W-CDMA
UMTS-TDD WiMAX: 802.16 standard
= Wireless Local Area Network= Wi-Fi: 802.11a, 802.11b, 802.11g,
802.11n, 802.11ac standards. = Wireless Personal Area Network and
most Wireless Sensor Actor Networks= 6loWPAN
Bluetooth V4.0 with standard protocol and with low energy protocol
IEEE 802.15.4-2006 Thread
UWB Wireless USB
ZigBee Overview
Notes: All speeds are theoretical maximums and will vary by a number of
factors, including the use of external antennas, distance from the tower and
the ground speed. Usually the bandwidth is shared between several terminals. The
performance of each technology is determined by a number of constraints,
including the spectral efficiency of the technology, the cell sizes used, and the
amount of spectrum available. For more information, see Comparison of wireless
data standards. For more comparison tables, see bit rate
progress trends, comparison of mobile phone standards, spectral efficiency
comparison table and OFDM system comparison table.
Peak bit rate and throughput When discussing throughput, there is
often a distinction between the peak data rate of the physical layer, the
theoretical maximum data throughput and typical throughput.
The peak bit rate of the standard is the net bit rate provided by the physical
layer in the fastest transmission mode, excluding forward error correction
coding and other physical layer overhead.
The theoretical maximum throughput for end user is clearly lower than the peak
data rate due to higher layer overheads. Even this is never possible to achieve
unless the test is done under perfect laboratory conditions.
The typical throughput is what users have experienced most of the time when
well within the usable range to the base station. The typical throughput is hard
to measure, and depends on many protocol issues such as transmission schemes,
packet retransmissions and packet size. The typical throughput is often even
lower because of other traffic sharing the same network or cell, interference
or even the fixed line capacity from the base station onwards being limited.
Note that these figures cannot be used to predict the performance of any given
standard in any given environment, but rather as benchmarks against which
actual experience might be compared. Downlink is the throughput from the base
station to the user handset or computer. Uplink is the throughput from the user
handset or computer to the base station. Range is the maximum range possible to
receive data at 25% of the typical rate. Typical spectral use
= Frequency= See also
Comparison of mobile phone standards List of device bandwidths
OFDM system comparison table Spectral efficiency comparison table
NFC RFID
CIR References
^ a b "LTE". 3GPP web site. 2009. Retrieved August 20, 2011.
^ a b c d e f "WiMAX and the IEEE 802.16m Air Interface Standard". WiMax
Forum. 4 April 2010. Retrieved 2012-02-07.
^ IPWireless ^ UMTS-TDD developer's frequency notes
^ IEEE 802.11, List of WLAN channels External links
Mobile WiMAX - Part I: A Technical Overview and Performance Evaluation
Mobile WiMAX – Part II: A Comparative Analysis
A Comparison of Bluetooth and IEEE 802.11
WLAN Trainer at different speeds IEEE 802.11 Standard Overview