What is Wireless?Many software companies and consulting firms are claiming newfound expertise in wireless these days. The biggest players in the web and application server market are touting that their servers are wireless enabled. Consulting firms are jumping on the bandwagon and using these servers to convince their clients of their own wireless expertise. What do these groups really know about wireless technology? With the adoption of the Wireless Application Protocol (WAP) by many of the mobile phone manufacturers in the U.S. and Europe, text-based data can be displayed on wireless phones and handheld devices using the Wireless Markup Language (WML). WML is a distant cousin of the HTML that's used to create full-sized web pages. People in Japan have it even better with their i-mode or Compact HTML technology that lets you view a miniature version of a full-color web page in a wireless phone or handheld device. There's nothing inherently wrong with these technologies. Being able to locate a restaurant or a movie theater from the convenience of your iPAQ handheld or StarTac mobile phone is a good thing. Most any software company or consulting firm has what it takes to deliver this kind of content to your phone or handheld. This is not rocket-science and it doesn't require any amount of wireless expertise to pull it off. So why are all these organizations claiming to be wireless experts? To get your business of course.
Nobody's HomeHow many times have you cursed your mobile phone for dropping your phone calls due to a lack of signal? Have you ever had full signal strength on your phone in your office on one day, only to have zero signal in the same spot a day later? This may explain why the so-called Mobile Commerce revolution has yet to take off. B2C and B2B e-commerce sites based on these miniature web pages delivered to your phone or handheld are only as reliable as the wireless network they're utilizing. Would you be inclined to enter your credit card number, cross your fingers, close your eyes, and hope that your e-commerce transaction goes through on your cell phone? I think not. The new players in this arena reveal their lack of understanding when it comes to wireless networks by building software in the same fashion that they did for wired networks like corporate LANs and the Internet. Too many costly assumptions are made.
Anticipate
Wireless networks are inherently unreliable. This fact alone means that you need to take another look at your assumptions and methodologies for software development. Anticipate an absence of signal strength. Anticipate that cellular towers may be down. Anticipate that the higher frequencies used by wireless networks have a hard time penetrating office buildings. Anticipate complete failure. These gloomy statements should now form the baseline for all future wireless development assumptions. When you accept this fact, you then realize that the miniature web pages provided by WML and i-mode are nothing more than dumb terminal screens that cannot be trusted for critical operations. You must adopt a framework that leads to the development of software that thrives even when the sky is falling. This means software that can anticipate a changing wireless environment must reside on the given wireless device.
Intelligent Software
All kinds of business applications are being built to run on mobile phones, Pocket PCs, Palms, Handsprings, and other wireless devices too numerous to count. These applications should be designed to excel at what they do while not concerning themselves with wireless network issues. Instead, they should hand off their data to a separate, intelligent software entity whose job it is to get that data to its final destination. When you send an overnight package to a business partner on the other side of the world, you don't concern yourself with how FedEx or UPS makes it happen. You just want your package to make it from point A to point B. So too should it be on a wireless device. The intelligent software that manages to get your data across the harsh wireless environment should provide you with easy to use interfaces that let your business applications plug right in. Whether the device connects via a wireless network, a modem, or a synchronization cradle, the software must be ready to react at a moments notice to the existence of a connected state in order to deliver its payload and guarantee its delivery.
Choose Wisely
Wireless networks are now becoming more mainstream than ever. Wireless LANs now travel at Ethernet speeds with a greater range and built-in security. Wireless data networks are now providing Internet coverage to many of the large metropolitan areas. Businesses of all sizes and disciplines are now seizing upon the advantages provided by wireless networks. This growth will continue to increase in step with the growing mobile workforce. When your business makes the eventual decision to move its Client/Server and Internet applications to wireless devices, do your homework and look for a partner that understands that building mission-critical wireless applications doesn't mean developing tiny web pages.
IntroductionA wireless local area network (WLAN) is a local area network (LAN) that doesn't rely on wired Ethernet connections. A WLAN can be either an extension to a current wired network or an alternative to it. Use of a WLAN adds flexibility to networking. A WLAN allows users to move around while keeping their computers connected.
WLANs have data transfer speeds ranging from 1 to 54Mbps, with some manufacturers offering proprietary 108Mbps solutions. The 802.11n standard can reach 300 to 600Mbps.
Because the wireless signal is broadcast so everybody nearby can share it, several security precautions are necessary to ensure only authorized users can access your WLAN.
A WLAN signal can be broadcast to cover an area ranging in size from a small office to a large campus. Most commonly, a WLAN access point provides access within a radius of 65 to 300 feet.
WLAN types
The private home or small business WLAN
Commonly, a home or business WLAN employs one or two access points to broadcast a signal around a 100- to 200-foot radius. You can find equipment for installing a home WLAN in retail stores like Office Max, Radio Shack, Target, and Walmart, among others.
With few exceptions, hardware in this category subscribes to the 802.11a, b, or g standards (also known as Wi-Fi). Home and office WLANs adhering to the new 802.11n standard are appearing. Also, because of security concerns, many home and office WLANs adhere to the Wi-Fi Protected Access 2 (WPA2) standard.
The enterprise class WLAN
This type employs a large number of individual access points to broadcast the signal to a wide area. The access points have more features than equipment for home or small office WLANs, such as better security, authentication, remote management, and tools to help integrate with existing networks. These access points have a larger coverage area than home or small office equipment, and are designed to work together to cover a much larger area. Such equipment adheres to the 802.11a, b, g, or n standard, though it's becoming common that equipment subscribes to security-refining standards, such as 802.1x and WPA2.
Wireless WAN (wide area network)
Although a WAN by definition is the exact opposite of a LAN, wireless WANs (WWANs) deserve brief mention here, especially because the distinction is becoming less and less obvious to end users.
WANs used to exist in order to connect LANs in different geographical areas (see What is the difference between a LAN, a MAN, and a WAN, and what is a LAN connection?). Until recently, this was also the case for WWANs. Now, cellular phone companies, such as Verizon (Broadband Access) and AT&T (Broadband Connect), offer WWAN technology that the end user can access directly.
The cellular WWANs use cellular data technology to cover extremely wide areas. Cellular WWAN data transfer rates are considerably slower than wireless LANs, with most advertising between 50Kbps to 2Mbps (compare this to dial-up speeds, which are around 56Kbps). Cellular WWANs rely on coverage by the cellular network provider, so coverage areas for wireless Internet access are more or less the same as they are for cellular phones. There are many different standards for this type of network. Most of them are mobile data standards that previously were used only on cell phones, but are increasingly offered for computing. Some manufacturers offer "mobile broadband" add-ons to their portable computers using the Sprint Broadband Direct, Verizon Broadband Access, and AT&T Broadband Connect networks.
WLAN standards
Several standards for WLAN hardware exist:
802.11a, b, and g
The 802.11a, b, and g standards are the most common for home wireless access points and large business wireless systems. The differences are:
* 802.11a: With data transfer rates up to 54Mbps, it is faster than 802.11b and can support more simultaneous connections. Because it operates in a more regulated frequency, it gets less signal interference from other devices and is considered to be better at maintaining connections. In areas with major radio interference (e.g., airports, business call centers), 802.11a will outperform 802.11b. It has the shortest range of the three standards (generally around 60 to 100 feet), broadcasts in the 5GHz frequency, and is less able to penetrate physical barriers, such as walls.
* 802.11b: It supports data transfer speeds up to 11Mbps. It's better than 802.11a at penetrating physical barriers, but doesn't support as many simultaneous connections. It has better range than 802.11a (up to 300 feet in ideal circumstances; tests by independent reviewers commonly achieve between 70 and 150 feet), and uses hardware that tends to be less expensive. It's more susceptible to interference, because it operates on the same frequency (2.4GHz) as many cordless phones and other appliances. Therefore, it's not considered a good technology for applications that require absolutely reliable connections, such as live video streaming.
* 802.11g: It's faster than 802.11b, supporting data transfer rates up to 54Mbps. It has a slightly shorter range than 802.11b, but still better than 802.11a. Most independent reviews report around 65 to 120 feet in real-world situations. It is backward-compatible with 802.11b products, but will run only at 802.11b speeds when operating with them. It uses the 2.4GHz frequency, so it has the same problems with interference as 802.11b.
802.11n
The Institute of Electrical and Electronics Engineers (IEEE) has not yet ratified the 802.11.n standard. Because of this, some manufacturers advertise their 802.11n equipment as "draft" devices.
Though specifications may change once the standard is finalized, it is expected to allow data transfer rates up to 600Mbps. Product manufacturers are advertising ranges twice as large as those of as 802.11b/g devices, but as with any wireless devices, range ultimately depends more on the manufacturer and the environment than the standard.
Security standards
The 802.11x standards provide some basic security, but they're becoming less adequate as use of wireless networking spreads. Security standards exist that extend or replace the basic standard:
WEP (Wired Equivalent Privacy)
One of the earliest security schemas, WEP was originally created for 802.11b, but migrated to 802.11a as well. It encrypts data traffic between the wireless access point and the client computer, but doesn't actually secure either end of the transmission. Also, WEP's encryption level is relatively weak (only 40 to 128 bits). Many analysts consider WEP security to be weak and easy to crack.
WPA (Wi-Fi Protected Access)
WPA implements higher security and addresses the flaws in WEP, but is intended to be only an intermediate measure until further 802.11i security measures are developed.
802.1x
This standard is part of a full WPA security standard. WPA consists of a pair of smaller standards that address different aspects of security:
* TKIP (Temporal Key Integrity Protocol encryption), which encrypts the wireless signal
* 802.1x, which handles the authentication of users to the network
Commonly, wireless systems have you log into individual wireless access points or let you access the wireless network, but then keep you from accessing network data until you provide further authentication (e.g., VPN).
802.1x makes you authenticate to the wireless network itself, not an individual access point, and not to some other level, such as VPN. This boosts security, because unauthorized traffic can be denied right at the wireless access point.
WPA2/802.11i
The Wi-Fi Alliance has coined the term "WPA2", for easy use by manufacturers, technicians, and end users. However, the IEEE name of the standard itself is 802.11i. The encryption level is so high that it requires dedicated chips on the hardware to handle it.
In practical use, WPA2 devices have interoperability with WPA devices. When not interfacing with older WPA hardware, WPA2 devices will run strictly by the 802.11i specifications.
WPA2 consists of a pair of smaller standards that address different aspects of security:
* WPA2-Personal, which uses a pre-shared key (similar to a single password available to groups of users, instead of a single individual); the pre-shared key is stored on the access point and the end user's computer
* WPA2-Enterprise, which authenticates users against a centralized authentication service
IU Secure, the new IU wireless network for students, faculty, and staff, uses WPA2 Enterprise for authentication.
