Specifications

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Other Standards
To future-proof your network, you need to incorporate wireless
technology into your structured cabling system. Plan on complete
wireless coverage, which, oddly enough, means more cabling not
less. It also means going through the alphabet soup of wireless
networking and infrastructure standards.
IEEE standards.
Some of the IEEE 802.11 standards are outlined below:
IEEE 802.11. Introduced in 1997, it supports speeds only up
to 2 Mbps and two different methods of encoding—Frequency
Hopping Spread Spectrum (FHSS) and Direct Sequence Spread
Spectrum (DSSS)—leading to incompatibility between equipment.
IEEE 802.11a uses the 5.8-GHz band called U-NII (Unlicensed
National Information Infrastructure) in the United States. It has
a higher frequency and a larger bandwidth allotment than the
2.4-GHz band, and achieves speeds up to 54 Mbps.
IEEE 802.11b. This extension boosts wireless throughput from
2 Mbps up to 11 Mbps. It operates in the 2.4-GHz band, one of the
most common. 802.11b can transmit up to 328 feet (100 m) under
good conditions. It dropped FHSS in favor of DSSS.
IEEE 802.11e. Ratified in 2005, this standard defines Quality
of Service (QoS) mechanisms for wireless. QoS makes it feasible to
operate bandwidth-sensitive applications such as voice and video.
IEEE 802.11g is an extension of 802.11b and operates in the
same 2.4-GHz band. It brings data rates up to 54 Mbps using
Orthogonal Frequency-Division Multiplexing (OFDM) technology.
802.11g is backward compatible with 802.11b, and an 802.11b
device can interface directly with an 802.11g access point.
IEEE 802.11i addresses many of the security concerns that come
with a wireless network by adding Wi-Fi
®
Protected Access (WPA)
and Robust Security Network (RSN) to 802.11a and 802.11b
standards. It loses security if used with non-802.11i devices.
IEEE 802.11n is, as of mid 2007, not yet ratified. This high-
speed wireless standard may achieve wireless throughput of up to
540 Mbps, although it’s expected that a more typical data rate will
be 200 Mbps. It will achieve these speeds by using a technique
called Multiple-Input/Multiple-Output (MIMO). MIMO transmits
multiple data streams simultaneously, increasing wireless capacity
while also increasing network reliability and coverage.
ISO/IEC TR 24704.
The ISO/IEC published the Technical Report 24704 in 2004 to
address wireless connections not specified in ISO/IEC 11801. It
addresses how to plan future wireless access point connections
Wireless networking
that supplement existing copper and fiber networks. It provides
guidelines on how to install the cabling prior to the wireless
implementation, and covers:
• Minimum configuration, structure, and topology.
• Performance requirements.
• Coverage and location of telecommunications outlets.
• Interfaces to wireless access points.
• Power delivery.
TR 24704 recommends using a dense wireless cell structure,
similar to a honeycomb pattern. Each cell has an operating radius of
12 meters (39.4 ft.), with one CAT5e (or higher) telecommunications
outlet in the center of each cell. The recommended distance
between outlets is 20 meters (65.6 ft.).
TIA TSB-162.
The TIA addresses cabling for wireless networking in TSB-162:
Telecommunications Cabling Guidelines for Wireless Access Points,
published in 2006. Like TR 24704, it provides guidelines on
topology, design, installation, and testing of wireless cabling
infrastructure. All its cabling recommendations are in compliance
with TIA/EIA-568-B.2 and TIA/EIA-569-B. It also addresses cabling
between network and wireless equipment and the pathways.
The primary difference between the TSB and the ISO/IEC
standard is the cell shape. The TIA recommends a square rather
than hexagon shape. Both standards recommend dense prewiring
and testing to make sure all possible areas are covered.
TR 24704 Wireless Grid
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Coverage Area
12 m
20 m