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Appendix d: glossary of terms – HP Radio Frequency Planner Software Series User Manual

Page 116

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Appendix D: Glossary of Terms

HP RF Planner User Guide

114

Appendix D: Glossary of Terms

This section provides a quick reference to wireless networking and Planner related terms and abbreviations used in this guide.

Table 3 Glossary of Terms
Term

Definition

Description

802.11

802 Series LANs

The IEEE 802.11 is a standard for WLANs. This standard is

developed to provide better and higher transmission rates.

AP

Access Point

An AP is an interface between wireless and wired networks. It

connects wireless Clients with an Ethernet to extend their range.

BoM

Bill of Material

Bill of Material is a detailed report that contains network inventory

along with the placement of APs and Sensors throughout the site. It

displays a list of APs and Sensors on each layout, their

configuration, the Vendor/Model Number, the protocol used and its

distance from the North-West corner.

Channel Interference

Channels are important to understand because they affect the

overall capacity of the Wireless LAN. A channel represents a narrow

band of radio frequency. A radio frequency modulates within a band

of frequencies; as a result of which there is a limited amount of

bandwidth within any given range to carry data. It is important that

the frequencies do not overlap or else the throughput would be

significantly lowered as the network sorts and reassembles the data

packets sent over the air.

The 802.11b specification operates at radio frequencies in the 2.4 to

2.497 GHz range and supports overlapping channels of 22 MHz

each. The frequency ranges and channels vary based on the

regulatory standards adopted by a country. For instance, in the US,

the FCC standard allows up to 11 channels whereas in Europe the

ETSI standard allows up to 13 channels.

When there are more than one source transmitting on a radio

frequency simultaneously, the receiver sees more than its partner

source. The receiver will have difficulties distinguishing one from the

other and the data will be lost. This is interference. Channels you

chose for the Clients and APs are susceptible to interference.

Therefore, it is important to ensure you are on the correct frequency

by selecting appropriate channels for the APs.

Layout Model

The model of the

Layout with all the

object placements

defined

After you import the layout image into Planner, the Layout Designer

helps designing the Layout Model. The Layout Model is a ready

layout of the entire layout for which you are performing WLAN

planning. The Layout Model contains all the objects, locations of

walls, windows, and doors with the details of the materials used in

it.

Layout Image

A .jpg, .gif image file of

the Layout

In the context of Planner, a Layout Image serves as the primary

input to the entire planning process.

RF Calculation Cell Size

Granularity of the RF

computations of the

WLAN signal strength

When you create a new plan, Planner determines the granularity of

the RF computations of the WLAN signal strength distribution

throughout the plan. It divides the plan into small units and then

calculates the RF characteristics for each unit. The size of a unit

determines the granularity of the RF computations and

computational time. Smaller the size of the unit, higher is the

granularity. However, this requires more time for WLAN signal

computations. Higher granularity also increases the amount of data

generated. The dimension of each unit is called ‘Factor’. A Factor of

four means that the plan is divided into 4x4 feet or 4x4 meters as

per the measurement unit in use. Planner has an in-built intelligent

algorithm to decide the granularity based on the size of the plan.

LAN

Local Area Network

A LAN usually resides in a single building or campus, and links the

computing resources together, typically by a cable.

Network Planner

A tool for planning the

WLAN in Planner

Network Planner helps you design the entire layout with the

specifications of the locations of the objects on the layout. It also

helps you plan the entire network after the placement of objects on

the layout is fixed. It allows you to drag and drop the devices such

as APs and Sensors on the layout model. This helps you try various