WIRELESS LANS

WIRELESS LANS<@VM>Access points and adapters cover the 2.4-GHz spectrum<@VM>Components of a wireless LAN range up to 11 Mbps in speed, 1,000 feet in distance

Radio frequency connections can add flexibility, scalability and security to your network, cutting overall costs

By J. B. Miles

Special to GCN





Proxim's RangeLAN2 Series includes a variety of access points and adapters, all with 1.6-Mbps data rates and 1,000-foot optimum ranges.
The units
operate
in the 2.4-GHz
frequency.



Now might be the time to consider a wireless LAN for your organization. The industry is hammering out standards and settling interoperability problems. And more products become available every month as the market for wireless LANs, now at $ 1 billion, grows by 40 percent to 60 percent annually.

Wireless LANs use radio frequency or infrared waves to transmit and receive data over the air instead of using copper or fiber-optic cable connections. Users don't have to search for a place to plug in to a wired network to gain access to shared information. Network managers can make quick network moves and changes without having to disconnect and reinstall a tangle of wiring.

A wireless LAN requires only two components: access points and adapters. Wireless access points are external transmitters and receivers'transceivers'that use an RJ-45, serial or other connection to link to a wired network.

Wireless adapters, equipped with transmit-receive capabilities and antennas, generally come in PC Card formats for notebook computers or as internal ISA/PCI cards for desktop PCs.

Other external adapters use serial or RJ-11 telephone connectors, and still others are fully integrated into handheld computers or scanners.





Lucent Technologies' WaveLAN series of products includes the WavePoint-II Access Point and several PC Card and ISA adapters, each with a range of 1,800 feet.


Most wireless LANs also come with an array of antenna options that can improve the direction, range or quality of the signal between the access points and adapters. And virtually all manufacturers provide software for setup and configuration.

Access points and adapters commonly used in wireless LANs are remotely manageable via Simple Network Management Protocol remote management software, and Wired Equivalent Privacy encryption is offered as an option with some software.

There are many benefits of wireless LAN technology. In a recent white paper, the Wireless LAN Alliance, a manufacturers' consortium in Redwood City, Calif., listed five:



Mobility. Wireless LANs give users access to real-time information anywhere in their organization.

Installation speed and simplicity. Installing a wireless LANs can be fast and easy because there's no need to pull cable through walls and ceilings.

Reduced cost of ownership. The initial investment costs for wireless LAN equipment may be slightly higher than the cost of wired LAN hardware, but overall installation expenses and lifecycle costs can be significantly lower.

Security. By virtue of the spread-spectrum technology that most radio frequency LANs are built around, they are inherently more secure than wired LANs.

Scalability. Wireless LANs can be configured in a variety of topologies to fit changing user needs. The configuration options can take two forms: independent peer-to-peer LANs and infrastructure LANs.

If two or more PCs are connected with wireless adapters, a mobile and flexible on-demand network can be set up in minutes. In an infrastructure LAN, when one or more access points are used to link mobile users to a wired LAN, hundreds of users may be served without the headaches of swapping out wires and cables.





The BreezNet Pro.11 series from Breeze Wireless Communications has optimum ranges of 2,200 feet for the PC Card adapter and 3,000 feet for other products.



Wide area popularity

According to a study commissioned last year by the Wireless LAN Alliance, the average return on investment for a wireless LAN was 8.9 months. And because wireless LANs supply all the benefits of wired LANs with few of the constraints, users love them.

Ninety-seven percent of users said wireless LANs met or exceeded their expectations, 92 percent reported a definite payoff from their use, and 92 percent said plans were under way to deploy more wireless LANs in the future.

Though there are other options (see story, Page 70), wireless LAN products operating in the 2.4-GHz spread-spectrum radio band are best for most users.

The 2.4-GHz band provides more bandwidth than the 900-MHz or 5.7-GHz radio spectrums, which are the only other radio frequency options. The wide 2.4-GHz band allows for relatively fast data throughput, between 1 Mbps and 11 Mbps, for large numbers of users. Because of its Industrial Scientific Medical designation, no license is required to use it.


The 2.4-GHz band also is where most of the IEEE 802.11 and Wireless LAN Interoperability Forum OpenAir standards are being finalized and where interoperability problems between various manufacturers' products are being solved.

Finally, it gives high levels of data security along with encryption options.




Glossary
Access point. A wireless device that transports data between a wireless network and a wired network.


Adapter. A wireless device that provides an interface between client hardware and the airwaves.


DSSS. Direct Sequence Spread Spectrum, one of two technologies used in 2.4-GHz radio frequency wireless LANs.


FHSS. Frequency Hopping Spread Spectrum, the other technology used in 2.4-GHz radio frequency wireless LANs.


IEEE 802.11. An Institute of Electrical and Electronic Engineers set of standards for wireless LANs.


Independent network. A wireless network that provides temporary peer-to-peer connectivity without relying on a complete network infrastructure.


IR. Infrared systems use high frequencies to carry data and are limited to short distances because IR cannot pass through opaque objects.


Industrial Scientific Medical. Unregulated 900-MHz, 2.4-GHz and 5.7-GHz bands that require no licensing fee.


Narrowband. Narrowband radio systems transmit and receive information on a specific and narrow radio frequency.


OpenAir. A standard developed by the Wireless LAN Interoperability Forum for 2.4-GHz wireless LANs that focuses on interoperability.


Packet radio network. Often used by state and local law enforcement agencies. Provides relatively slow 19.2-Kbps throughput.


PAN. Personal area network, a short-range point-to point wireless system for personal and small office, home office use that often uses infrared technology.


Radio frequency terms. Hertz is the international standard for measuring frequency in cycles per second. Megahertz is 1 million hertz.'Gigahertz is 1 billion hertz.


Wireless node. A user computer with a wireless network adapter.


WMAN. Wireless metropolitan area network, usually developed by a third-party provider that charges fees based on bandwidth use or time.


WWAN. Wireless WAN, often developed by using wireless bridges between LANs.



Basic 2.4-GHz access points with an RJ-45 Ethernet connector cost between $1,000 and $2,000, depending on options. Client adapters tend to cost between $295 and $695, depending on configurations.

Most of them operate at 100-milliwatt power levels, though some operate at 500 milliwatts.

The range for most 2.4-GHz LAN components running at 1 Mbps or 2 Mbps is from 500 feet indoors to 1,000 feet outdoors, but other factors such as interference sources, number of users and topography must also be entered into the equation.

Site monitoring and link surveying software bundled with many wireless products can help users determine their optimum configurations.

Along with 900-MHz and 5.7-GHz radio frequency systems, 2.4-GHz wireless LANs use spread-spectrum technology that was developed years ago by the military.

Simply stated, spread spectrum trades off bandwidth efficiency for security and reliability.



If the receiver knows the parameters of the spread spectrum signal, the signal itself comes in loud and clear. If it doesn't, the message looks like background noise to an unintended receiver.

But to further confuse the uninitiated, there are two types of spread-spectrum techniques: Frequency Hopping Spread Spectrum (FHSS) and Direct Sequence Spread Spectrum (DSSS).

FHSS uses a narrowband carrier that hops, or changes frequencies, in a pattern known to both the transmitter and receiver. If synchronized, the signal occurs clearly as if it were on a single, logical channel. If not synchronized, the signal appears as indecipherable short-duration noise.

DSSS produces a redundant bit pattern called a chip or chipping code for each bit to be transmitted.

The longer the chip, the easier it is to recover original data if contaminated. DSSS appears as low-power wideband noise to unintended receivers.

Proponents of each technology continue to argue their respective merits, and the systems listed in this guide are evenly split when it comes to the use of FHSS and DSSS.

DSSS' proponents claim it is the logical pathway to the 11-Mbps throughputs of the future.

That point is supported by the fact that 3Com Corp.'s new 11-Mbps AirConnect and Aironet Wireless Communications Inc.'s Aironet 11-Mbps 4800 Series are both based on DSSS technology.

FHSS is less expensive to implement than DSSS, but it requires more access points to gain 11-Mbps throughput.'DSSS transceivers are more expensive, but operate at longer ranges, thus requiring fewer access points.

J.B. Miles, of Pahoa, Hawaii, writes about communications and computers.

Vendor

Product

Form factor

Data

rates

in Mbps


Optimum

range in

feet


Features

Price

Aironet Wireless

''Communications Inc.

Akron, Ohio

330-664-7900

www.aironet.com




AP4800 Turbo DS

Access point

1, 2,

5.5, 11


1,800

Remote management and

configuration; site survey

tools; automatic load balancing


$1,695


PC4800 Turbo DS

PC Card adapter

1, 2,

5.5, 11


1,800

High-gain antenna options

$595


MC4800

External adapter

1, 2,

5.5, 11


1,000

Capacity for up to four clients;

LED indicators


$1,445


PCI & ISA4800

PCI/ISA adapter

1, 2,

5.5, 11


1,000

High-gain antenna options

$695 to

$725



UC4800

External serial

adapter


1, 2,

5.5, 11


1,000

Universal adapter for

printers, PCs, point-of-sale

devices, other peripherals


$1,045 to

$1,095





AP4500

Access point

1, 2

2,000

Web management; support

for wireless repeaters


$1,595


PC4500

PC Card adapter

1, 2

1,800

Automatic data rate fallback

$495


MC4500

External adapter

1, 2

2,000

Capacity for up to four clients;

LED indicators


$1,345


PCI & ISA4500

PCI/ISA adapter

1, 2

2,000

High-gain antenna options

$595 to

$625



UC4500

External adapter

1, 2

2,000

Universal adapter for

printers, PCs, point-of-sale

devices, other peripherals


$945 to

$995





AP3500

Access point

1, 2

1,800

Remote management and

configuration; filtering;

support for wireless repeaters


$1,595


PC3500

PC Card adapter

1, 2

1,000

High-gain antenna options

$495


MC3500

External adapter

1, 2

1,000

Capacity for up to four clients;

LED indicators


$1,345


PCI & ISA3500

PCI/ISA adapter

1, 2

1,000

High-gain antenna options

$595 to

$625



UC3500

External adapter

1, 2

1,000

Universal adapter for

printers, PCs, point-of-sale

devices, other peripherals


$1,345


Bay Networks Inc.

Santa Clara, Calif.

408-988-2400

www.

''netwave-wireless.com




BayStack 650

Wireless Access Point


Access point

1

1,000

Bundled with site survey and

management software


$1,499


BayStack 650

Wireless PC Card


PC Card adapter

1

1,000

Integrated antenna

$499




BayStack 660

Wireless Access Point


Access point

1, 2

2,000

Bundled with site survey and

management software


$1,799


BayStack 660

Wireless Access Point


PC Card adapter

1, 2

2,000

Integrated antenna

$569

Breeze Wireless

''Communications Inc.

Carlsbad, Calif.

760-431-9880

www.breezecom.com




AP-10 PRO.11

Access point

1, 2, 3

3,000

SNMP remote management;

external high-gain antenna option


$1,295


SA-10 PRO.11

External adapter

1, 2, 3

3,000

Connects to any Ethernet-

enabled device; LED indicators


$695


SA-40 PRO.11

External adapter

1, 2, 3

3,000

Same; capacity for up to four

devices


$1,195


SA-PCR PRO.11

PC Card adapter

1, 2, 3

2,200

Built-in retractable antenna

$495

Cabletron Systems Inc.

Rochester, N.H.

603-332-8007

www.cabletron.com




SmartSwitch

RoamAbout

Access Point


Access point

1, 2

1,200

Connectivity via Ethernet RJ-45

or twisted-pair connections;

RMON-enabled management


$1,295


SmartSwitch

RoamAbout

2.4-GHz PC Card


PC Card adapter

1, 2

1,200

Optional indoor antenna

$295


C-SPEC Corp.

Dayton, Ohio

937-439-2882

www.c-spec.com


PCC2LDS2

PC Card adapter

1, 2

656

Remote boot; DES encryption

option


$295


PCC2LDST

PC Card adapter

4

656

Same

$495

Hand Held Products Inc.

Charlotte, N.C.

704-537-1444

www.handheld.com

'




Ethernet Access

Point


Access point

1.6

1,000

WLIF OpenAir compatibility;

can link Dolphin RF handheld

computers


$1,895


2.4-GHz RF PC Card

PC Card adapter

1.6

1,000

WLIF OpenAir certified for

interoperability; dipole and

snap-on antenna options


$745


2.4-GHz RF ISA Card

ISA adapter

1.6

1,000

Same

$595

Intermec

''Technologies Corp.

Chevy Chase, Md.

301-654-9235

www.intermec.com




Univeral Access

Point 2100


Access point

1, 2

1,800

Operates in the 2.4-GHz DSSS,

2.4-GHz OpenAir, 2.4-GHz FHSS

and 900-MHz RF spectrums


2,280 to

$3,085



Universal Access

Point 2101


Access point

1.6

1,000

Supports all current wireless

LAN standards


$1,495 up


Model 0111

Access point

1.6

1,500

WLI Forum OpenAir-compatible

$2,280


Model 0115

Access point

1.6

1,500

Supports token-ring networks

$2,695


2.4-GHz OpenAir

ISA Card


ISA adapter

1.6

1,500

Connects to Norand Open

Wireless LAN


$595


2.4-GHz OpenAir

PC Card


PC Card adapter

1.6

1,500

Connects to Norand Open

Wireless LAN


$695


Lucent

''Technologies Inc.

Murray Hill, N.J.

908-582-8500

www.lucent.com


WaveLAN Series (DSSS)


WavePoint-II

Access Point


Access point

1.6

1,800

WaveManager SNMP

management software


$1,077


WaveLAN IEEE Turbo

PC Card adapter

PC Card (Bronze)


1, 2

1,800

Offers high, medium,

standard and stan-

dard low speed

options


$429


WaveLAN IEEE 802.11

PC Card (Bronze)


PC Card adapter

1, 2

1,800

Site monitoring; link surveys;

IEEE 802.11-compliant


$256


WaveLAN IEEE PC

Card - WEP (Silver)


PC Card adapter

1, 2

1,800

Wired Equivalent Privacy

encryption; IEEE 8.2.11-

compliant


$299


WaveLAN IEEE Turbo

ISA Card (Bronze)


ISA adapter

1, 2

1,800

Offers high, medium,

standard and standard

low speed options


$516


WaveLAN IEEE 802.11

ISA Card (Bronze)


ISA adapter

1, 2

1,800

Site monitoring; link surveys;

IEEE 802.11-compliant


$342


WaveLAN IEEE ISA

Card-WEP (Silver)


ISA adapter

1, 2

1,800

Wired Equivalent Privacy

encryption; IEEE 8.2.11-

compliant


$386


NCD Communications

''Inc.

Sunnyvale, Calif.

408-730-0888

www.ndclan.com




Access Point

NW660A


Access point

1, 2

1,000

Dual-diversity antenna;

site survey tools; intelligent

roaming; automatic reboot;

remote firmware upgrades;

SNMP management


$1,295


ISA Card

NW620A


ISA adapter

1, 2

1,000

External antenna; site

surveying; self-diagnostic

software


$429


PC Card

NW610A


PC Card adapter

1, 2

1,000

Integrated antenna; site

surveying; self-diagnostic

software


$429


Nokia Wireless

''Business

''Communications

Ottawa

877-386-2276

www.nokia.com




A020 Wireless LAN

Access Point


Access point

1, 2

1,000

Supports up to 500 devices;

access security; Web

browser management

configuration


$1,295


A021 Wireless LAN

Access Point


Access point

1, 2

1,000

Same, with modem for

dial-up networking to

Internet service providers


$1,295


C020 Wireless LAN

Card


PC Card adapter

1, 2

1,000

Integrated antenna

$295


C021 Wireless LAN

Card


PC Card adapter

1, 2

1,000

External antenna

$310


OTC Telecom Inc.

San Jose, Calif.

408-245-6888

www.ezylink.com




AirEZY240-SWG

External adapter

1, 2

1,000

Platform-independent

$495


AirEZY2405-SWG

External adapter

5.5

600

Platform-independent;

optional battery pack


$595

Aironet 4800 Series (2.4-GHz DSSS)

Aironet 4500 Series (DSSS)

Aironet 3500 Series (2.4-GHz FHSS)

BayStack 650 Series (FHSS)

BayStack 660 Series (DSSS)
BreezeNET PRO.11 Series (DSSS)
SmartSwitch RoamAbout Series (DSSS)
Dolphin RF (FHSS)
Intermec INCA 2.4GHz (DSSS, FHSS)

InstantWAVE (FHSS)

Nokia Wireless LAN (DSSS)

AirEZY (DSSS)


Proxim Inc.

Sunnyvale, Calif.

408-731-2700

www.proxim.com




7510 RL2

Ethernet AP


Access point

1.6

1,000

Choice of Telnet, SNMP, Web

browser management


$1,595


7520 RL2

Ethernet AP


Access point

1.6

1,000

Same

$1,895


7521 RL2

Ethernet AP


Access point

1.6

1,000

Same with 500-megawatt

power output


$1,895


7530 RL2 Token

Ring AP


Access point

1.6

1,000

Choice of Telnet, SNMP, Web

browser management


$1,895


7531 RL2 Token

Ring AP


Access point

1.6

1,000

Same with 500-megawatt

power output


$2,495


RangeLAN2 7100

ISA Card


ISA adapter

1.6

1,000

OpenAir compatibility

$695


RangeLAN2 7401/2

PC Card


PC Card adapter

1.6

1,000

Integrated antenna or

snap-on antenna option


$595 to

$695



RangeLAN2 7410

CE PC Card


PC Card adapter

1.6

1,000

Designed for Windows CE

handheld PCs


$295


RangeLAN2 7910/11

Series Serial Adapter


External serial

adapter


1.6

1,000

Connects with devices via

RS-232C serial ports


$895


RangeLAN2 7920/21

Series Ethernet

Adapter


External adapter

1.6

1,000

Connects any device via

an RJ-45 Ethernet connector


$895




RangeLAN802

8520/21 Series

Ethernet Access Point


Access point

1, 2

1,000

Remote management via

Telnet, SNMP or dial-up

lines; WEP encryption;

built-in RISC processor


$1,895


RangeLAN802

PC Card


PC Card adapter

1, 2

1,000

Available in both 100-megawatt

and 400-megawatt configurations


$595


RangeLAN802

8401/02 Series

PC Card


PC Card adapter

1, 2

1,000

Dipole and snap-on

antenna options


$595


Raytheon Electronics

  Wireless Solutions

Andover, Mass.

800-457-6811

www.raylink.com




Raylink Access

Point


Access point

1, 2

1,000

Multiple antenna options;

includes Raylink PC Card


$1,495


Raylink PC Card

PC Card adapter

1, 2

1,000

Extended one-piece design

with built-in antenna


$495


Symbol

  Technologies Inc.

Holtsville, N.Y.

516-738-5200

www.symbol.com




AP 2411 Ethernet

Access Point


Access point

1, 2

1,000

Built-in diagnostics; SNMP

Agent; packet tracing; event

logging


$1,495


LA 2400 Wireless

LAN PC Card Series


PC Card adapter

1, 2

1,000

Flash memory software

upgrades


$395


LA 2470 Wireless

LAN adapter


ISA adapter

1, 2

1,000

Flash memory software

upgrades


$495


3Com Corp.

Santa Clara, Calif.

408-326-2500

www.3com.com




AirConnect

Access Point


Access point

11

400

40-bit and higher encryption

option for government users


$1,700


Wireless PC Card

PC Card adapter

11

400

Same

$300


RangeLAN2 Series (FHSS)

RangeLAN802 Series (FHSS)

Raylink Wireless LAN (FHSS)

Spectrum24 2-Mbps FH Wireless LAN (FHSS)

AirConnect (DSSS)

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