Windows Foundation

Hi-Wireless Act

It's a confusing wireless world out there. We sort through the protocols that are gaining momentum.

Suppose that you have a group of users who'd really benefit from being able to take their laptop, PDA or tablet PC with them and wirelessly connect with the network from any location. Really cool idea, right? But exactly how do you go about accomplishing this lofty goal?

There are several different wireless methodologies that are loose in the world—some more popular than others but not necessarily technologically superior. In this article, we'll look at the technologies that are making headway onto corporate networks and look at the design decisions that may affect you as you try to keep those roaming users connected.

Bluetooth
Bluetooth (see www.bluetooth.com) is fairly new—in fact, the specifications for it are not yet fully developed. It allows for low-powered Bluetooth-compatible devices to communicate with one another in the unlicensed 2.4 GHz radio frequency range. This band was originally intended for industrial, scientific and medical (ISM) applications but is now being leveraged for wireless networking activities, not just by Bluebooth but also by other standards.

Bluetooth uses a spread spectrum, frequency hopping, full-duplex signal that is able to hop from one frequency to the other at up to 1,600 hops per second. There are 79 frequencies 1 MHz apart from one another that can be used by Bluetooth. This frequency hopping characteristic sets up a good secure environment for the Bluetooth users.

You must have at least two Bluetooth-compatible devices in order to be able to set up a Bluetooth wireless network. Bluetooth technology is designed with the "Personal Area Network" (PAN) in mind—not the stuff you need for large networks. You can't run a backbone or LAN off a Bluetooth environment. In fact, you're limited to eight devices within a single Bluetooth PAN—called a Piconet. Additionally, you're limited to a 30-foot distance between devices. I wanted to set up a Bluetooth network between a USB Bluetooth device I purchased for my wife's computer and her Bluetooth-equipped Compaq iPAQ so that she could access information on her PDA while sitting out on our deck. But I couldn't accomplish my mission because her PC is farther away from our deck than the 30-foot Bluetooth distance limit. (Note that Bluetooth does not require the two devices to point directly to one another as infrared [IR] devices do.)

You can use Bluetooth to connect a Bluetooth-supported PC to a cell phone, PDA and perhaps a printer in a PAN so that you eliminate the personal workspace cable mess. The devices participating in the PAN are said to be in the "Bluetooth neighborhood" which shows up in the Bluetooth software that comes with the devices. If a person in your office needs to make use of this kind of close-quarters networking, then Bluetooth is a great choice.

Bluetooth has a huge shortfall, though. Its newness produces large technology gaps, holes that you might clamor to have filled. In my wife's case, for example, she had three basic requirements:

  1. Surf the Internet from her iPAQ.
  2. Send and receive e-mail.
  3. Send and receive files.

A Sad Story
The Bluetooth USB adapter we purchased for her PC installed just fine, as did its supporting software. Upon pointing the iPAQ at it, it was exciting to see both devices show up in the Bluetooth neighborhood! However, functionality was very limited and I was disturbed to find out that she was not going to be able to surf the Web or send/receive e-mail via her PDA. She could send/receive file or cached Web pages that her Active Synch software had cached for her at the PC, but couldn't actively utilize the Internet.

In a reply from an e-mail I sent to "The New HP's" help-desk I was informed that I needed to purchase a Bluetooth backpack for the iPAQ—even though it already had an on-board Bluetooth chip. Turned out that this was bad help-desk advice and I really didn't need the $189 device. The Bluetooth USB adapter vendor said that that I couldn't accomplish my mission with the materials I currently had.

Turns out that in order for Bluetooth to be a viable Internet option, it has to "see" an ISP that supports Bluetooth. For example, if I had had a Bluetooth cell phone that had an Internet connection, then I'd be able to accomplish my goal. But my non-Bluetooth-aware AT&T Broadband account wouldn't be able to cut the Bluetooth mustard.

So, here's the long and short of Bluetooth: I'm not sure it's ready for prime time, especially in the business arena. But stay tuned because the members of the Bluetooth SIG (Compaq…er… "The New HP" among them) are hot to utilize this new technology. It has worldwide governmental standardization and folks are working hard to find a niche for this nifty technology.

Things to Think About with Bluetooth
Because Bluetooth uses the same 2.4 GHz spectrum that 802.11b (Wi-Fi) uses (more on this later), I wonder if you might get some interesting radio interference if you put Wi-Fi and Bluetooth devices near one another?

Blackberry
Blackberry is a wireless e-mail technology developed by Research in Motion (Rim) Corporation (see www.blackberry.net or www.rim.com for more information). The technology requires a Blackberry-equipped device and either a subscription to a Blackberry service such as those provided by AT&T Wireless, Cingular and others, or through a Blackberry Enterprise server.

Blackberry solutions have been developed for enterprise-class e-mail server software such as Microsoft Exchange and Lotus Domino Server. Blackberry devices of varying ranges of sophistication can be obtained—everything from simple e-mail transfers to support for voice, e-mail attachments, data transfer, paging and other elements.

Blackberry operates in three different frequencies: 800 MHz, 900 MHz or 1900 MHz. There have been some questions as to whether Blackberry devices might interfere with formal radio systems (such as police radios) operating close by in the same range.

Blackberry might be a great choice for environments in which you need to get simple messages to a variety of geographically separated people. A uniform-delivery service, for example, operating trucks in a metropolitan area might be able to make good use of Blackberry.

However, security and potential interference with other radio systems in the same area—800 and 900 MHz systems are the bread and butter of most radio networks—need to be elements that are on the forefront of a wireless network designer's mind when considering a Blackberry deployment.

802.11
Now, here's the really interesting wireless science—the one that you'll most probably consider deploying in your enterprise. This technology is called "Wi-Fi"—short for Wireless Fidelity—in an effort by a group of manufacturers and others interested in the technology (see www.weca.net/OpenSection/index.asp and www.802.11-planet.com for more info) to bring brand and class identification to the field. When we talk about Wi-Fi, we could be referring to one of two different types of the IEEE 80211 specification:

  • 802.11b—In this, the most commonly used of the two 802.11 specifications, you're dealing with 2.4 GHz, the same spectrum that Bluetooth and microwave ovens operate in. There is a veritable plethora of 802.11 devices available and ready for use today to equip everything from the home network to the enterprise-level WAN or ISP base.
  • 802.11a—This specification provides for wireless connectivity in the 5 GHz spectrum, thus eliminating today's problem of Bluetooth and other company's 802.11 devices potentially crowding out the frequencies you're operating in.

The 802.11 standard can support a couple of different architectures for wirelessly-equipped devices to connect to the network:

SEA
Suppose that you have several laptop computers, all equipped with 802.11 devices and these laptops need to connect to one another without benefit of any cabling. In this case an algorithm called Spokesman Election Algorithm (SEA) can be utilized in an 802.11 environment. SEA and others like it call for one master base station to be elected so that all laptops can communicate with one another.

WAP
The more common wireless connection environment is one that utilizes Wireless Access Points (WAPs). A WAP is a hardware device that connects to the LAN and provides radio connectivity (as both a transmitter and receive—a transceiver) to the network for wireless devices. You can purchase Small Office Home Office (SOHO), Small- to Mid-sized Business (SMB), or enterprise-class WAPs, depending on the size of your organization, for connectivity to the LAN. The New HP, for example, sells the WL310 Home Office Gateway, the WL410 Small Business Access Point and the WL510 Wireless Enterprise Access Point, all Compaq devices. Cisco Corporation and others also offer a wide variety of enterprise-scale WAP devices.

Interested in setting up an 802.11 wireless network at work? You just need a few parts:

  • A WAP
  • Wireless PC cards or NICs for your computers and PDAs
  • If you're interested in letting your users access their e-mail and calendars from wirelessly-equipped devices you'll also need to have Microsoft Mobile Information Server 2003 installed and configured. (Noting that this also requires that you have Windows 2000 Active Directory and Exchange 2000 up and operational as well).

Things to Think About with 802.11
Three words: Security, security, security. Hackers have a new game they play called "warchalking." Unlike artists who like to use public sidewalks for their canvas, warchalking hackers roam city corridors with an 802.11 device looking for entry onto corporate wireless networks. Once they find a connection, they chalk the building or the sidewalk to denote that they've gotten in.

Many enterprise-class 802.11 devices come with a firewall that helps you manage rogue intrusion into the network—but still and all rigorous management of your DHCP scopes and monitoring of your wireless traffic are in order when considering the widespread use of a wireless network.

While WAPs provide a way for your wireless users to connect to the network, you'll want to set up wireless encryption in such a way that you meet your security policies. Maintaining security in a wireless LAN (called a WLAN) can create significant difficulties for administrators.

Ricochet
Ricochet (www.ricochet.com) supplies wireless connectivity to the Internet using a proprietary protocol and associated hardware. Today Ricochet has live deployments in Denver and San Diego, with one planned for Dallas/Fort Worth.

Because of Ricochet's Metropolitan Area Network (MAN)-based technology, this is a good choice for companies in these cities to take into consideration.

Getting Wired Up with Wireless
Your selection of an appropriate wireless environment will depend in large part on the type of geographic distances your wireless users will be connecting from (across the hall; across the campus; across the city; across the country; across the world). An 802.11 WLAN won't be helpful if you're in Detroit and an executive wanting to wirelessly connect needs to do so from Beijing. (In such a case, a Blackberry subscription and Blackberry-supported device for this user would be the logical choice).

Apart from this rarity, the majority of uses you'll be able to envision for your wireless network center on users connecting in some sort of metropolitan environment (or closer). In most cases, 802.11 will be the network of choice because it's easy to deploy, standardized, there's a wide variety of equipment available and it's well-understood (i.e. training and books are readily available).

If I were simply considering users who only wanted access to the Internet and their e-mail—who did not require VPN connections for access to applications, files or the intranet/portal—then I'd probably choose a 802.11 network over the Blackberry Enterprise server to hook into my network. Blackberry services are costly, as are Blackberry devices.

In all cases, the client configuration characteristics with regard to their security settings will be of high importance. You'll want to make sure that your users utilizing wireless technologies can't be hacked and that hackers can't gain entry to your wireless network. (To find out more about security, check out Roberta Bragg's column this month.)

Note that wireless networks are not performers, in terms of speed. The 802.11 speeds vary depending on the distance the remote device is away from its base, as well as various building characteristics (concrete vs. drywall, etc.) Plan on a whopping maximum 11 MB/s out of 802.11 network, but be pleasantly surprised if you get anywhere close. Bluetooth operates at the 1 MB range. Users of any of the wireless networks will find much slower performance than they're accustomed to at the local desktop.

Your customer care operations will need to be aware of the differences involved in a wireless user connecting as opposed to a normal LAN-cabled user. Plan on help-desk calls coming from wireless users—calls that may bewilder your staff if they've not had a chance to experiment with this new technology.

comments powered by Disqus

Redmond Tech Watch

Sign up for our newsletter.

I agree to this site's Privacy Policy.