Wireless Wide Area Networks: Trends and Issues Wireless Wide Area Networks: Trends and Issues

Mobile computing devices are getting smaller and · Specialized equipment and custom applications more powerful, while the amount of information is were needed for deployment over these propri- growing astronomically. As the demand for con- etary wireless systems. necting these devices to content-rich networks · Often the wireless infrastructures themselves rises, WWAN technology seems like the perfect were difficult to deploy. answer. But today's wireless WANs have some lim- itations. This white paper discusses those limita- · Only a small percentage of the working popula- tions and how NetMotion™ overcomes them. tion was mobile, so corporations considered wireless data deployment a significant invest- Historic Trends ment with little return. Wireless wide area data networking is not a new Why the resurgence of interest in wireless data net- phenomenon. The technology has been around for working technologies now? In the late twentieth over 100 years and was used to send information century, a few interesting social and technological well in advance of voice systems. But as radio tech- developments took place. In the late 1990's, busi- nology progressed, the use of radio transmissions nesses began seeing the economic benefit of having for voice became dominant. It was a natural inter- employees who work away from their campuses. face for people to use, and—temporarily—wireless These remote (and sometimes nomadic) workers data transmission became less important. needed access to everyday corporate information to do their jobs. Providing workers with remote In the twentieth century, voice transmission took a connectivity became a growing challenge for the big step with the birth of the cellular concept at information staff. Handheld and pocket-sized Bell Labs in 1947. Not until 1979 were the first computers became powerful enough to be useful. direct dial analog cellular systems deployed in The convergence of Internet networking technolo- Japan. The Nordic countries followed by 1981. Two gies made IP the de facto standard. New standards years later, the U.S. installed the first commercial such as General Packet Radio Services (GPRS) Advanced Mobile Phone Service (AMPS) wireless were being adopted to provide wireless network cellular system in Chicago. Soon it was apparent services. With the development of such technology, that higher capacity, more reliable, and lower cost the promise of faster access speeds from new wide wireless systems were needed to meet growing area wireless interconnects began to approach (or consumer demand. Over the past decade or so, sig- in some cases exceed) standard connections over nificant efforts were made to increase the capacity landlines. These factors created the environment and robustness of these voice systems, thus the for the anytime, anywhere connected worker. development of the digital standards. Wireless WAN Definition It would seem that technology for wireless data communication over radio signals was left behind. A wireless Wide Area Network (WWAN) is a com- But there were many successful efforts over the puter data network that may extend over a large years to provide "wireless" connectivity, including geographical area. Characteristically, a WWAN IBM and Motorola's ARDIS network, Ericsson's receives and transmits data using radio signals Mobitex, and cellular digital packet data (CDPD). over the initial interconnect with the mobile com- These technologies and others continue to provide puter system. At the switching center, WWAN seg- connectivity for many specialized applications ments then connect to either a specialized public or today. private network via telephone or other high-speed There are many reasons why these technologies communication links. These back-haul intercon- did not have broad commercial appeal and why nects then link to an organization's existing LAN/ the time wasn't right: WAN infrastructure. Recent developments now · While computers grew smaller, most were still allow direct connections to generic public net- too bulky to carry around. works, like the Internet, further reducing the cost of deployment.

2 Unlike wireless local area networks (WLANs), the or slower. The average access time may be slower coverage area for WWANs is normally measured than a 28.8 modem connection. Wireless networks in miles rather than feet. Data throughput rates for in general are also more susceptible to environ- WWANs are a great deal slower than they are for mental factors, like weather and terrain, than local area network connections. They are typically wired networks. measured in tens of thousands of bytes per second

Figure 1—Components of a wireless WAN Wireless WAN Limitations

Wireless WAN Benefits Mobile computing devices are getting smaller, cheaper and more powerful. At the same time the Whether they are in the office or traveling, today's amount of information available today is growing professionals need access to the corporate data and astronomically. The demand for connecting mobile applications that keep them connected to their devices to content- organization's processes. Wireless WAN connectiv- ity means hospitals can track patients and their rich networks is also rising quickly, and it would charts remotely. Sales staff have access to the latest seem that WWAN technology is the perfect product information for customer presentations. answer. But today's wireless WANs have limita- Managers can get the latest data to make decisions tions in several areas, including: when they are away from their offices. Or public · safety officials can access data that they need from Security the field. · Performance It is access to data communications connections · Application persistence wherever and whenever they are needed that is · Roaming driving the market. Dataquest Inc., the San Jose- based research firm, projects that the wireless data · Off-the-shelf solutions market will grow from 3 million subscribers this · Central management year to 36 million in 2003. Cahners In-Stat's num- bers, while lower (2 million users in 1999 growing to 25 million in 2003), echo similar growth. Both agree that in the near term, it is corporate users who will drive this growth. This business demand will eventually lower future wireless access costs and open the doors to the consumer market.

3 To overcome these limitations, organizations usu- area. They may also choose to suspend operations ally have to increase their already steep IT work- to extend battery life. Such normal communication load by developing point solutions. What follows interruptions can wreak havoc with existing trans- is a more detailed look at these problem areas. port protocol implementations and cause user applications to either lock up or terminate. Security: In modern network topologies, physical boundaries between public and private networks To minimize such interruptions, most wireless are blurring. Unless care is taken, when a company solutions require customizing both the applica- decides to add wireless connectivity to this mix, tions and the network. As a result, most current their information security can be compromised. solutions are limited in scope and restricted to a Wireless systems in general broadcast data over specific set of applications. The radio waves into the ether. The security implica- mission-critical applications are still relegated to tions are obvious—what companies broadcast goes stationary or desktop systems. When a company everywhere. One of the first concerns that the IT tries to deploy these applications to their mobile department has is whether the information cross- devices, mobile users spend a lot of time getting ing the wireless network boundary is secure, back on the network after losing their connections. because it is susceptible to eavesdropping. Sec- They must re-login, re-authenticate, possibly navi- ondly, they must feel confident that a user has the gate through multiple screens to find the point necessary network permissions to access informa- where they left off, and then re-enter any lost data. tion, since they cannot rely on the mobile device's In the end, users become frustrated and feel unpro- physical location to tell them. Wirelessly connected ductive, which costs the company precious time devices can easily breech two of the most funda- and money. mental network security policies: authentication and confidentiality. Roaming: Over the past several years, network Performance: Things never encountered in wired installations have been segmented for manage- infrastructures affect wireless connections: envi- ment and security reasons. To aid network seg- ronmental factors, such as user movement, har- mentation deployment, the networking industry monics, terrain, and weather, can easily affect has worked hard to allow dynamic configuration throughput and performance. Today's standard of systems when they attach to a particular seg- network topologies and protocol implementations ment. However, once application sessions are were designed for communications between sta- established over existing protocols, the network tionary systems. In general, when a mobile device assumes that a device remains attached to that seg- communicates with a stationary device, the sta- ment for the duration of the session. But mobile tionary system uses the same algorithms to com- devices can wander to different areas and the com- municate with its mobile peer. It is not aware that munications pipe can be easily broken. To avoid the device is mobile, and it is this lack of awareness this, companies have had to either re-architect their that is at the heart of most performance problems. network interconnections or customize their appli- Application performance can further degrade cations, both of which cost time and money. when generic transport implementations intended Standard off-the-shelf applications: Most compa- for stationary devices are deployed on mobile nies do not own the source code for applications ones. that they use to access their mission-critical infor- mation, especially the networking components. Another concern is how these generic solutions They either purchase canned applications or librar- deal with user movement across network seg- ies that enable access to the stored information. If ments. Since mobility was never considered when the latter is the case, these libraries (in binary form) most networks were originally designed, addi- are then linked in to customized front-end applica- tional information is required at the protocol layer. tions. These "off-the-shelf" applications may suffer This additional overhead can further reduce over- from the mobility problems mentioned above. To all performance and provide less than optimal re-customize each important application for throughput over wireless connections. mobile deployment strains the IT department's Application persistence: Because users with wire- personnel resources and increases the time and less devices are not tethered to a fixed intercon- cost of deployment. Once completed, the newly nect, they can unwittingly move out of a coverage

4 customized application may require retraining and rithm), and compressed again using industry stan- extend the deployment timeline because of a com- dard deflate/inflate algorithms, similar to a Virtual plex installation. Private Network. NetMotion further integrates the standard user and group attributes with the Centralized management and efficient use of IT Microsoft NT security system. Using these stan- resources: Troubleshooting a network problem is dards enables NetMotion to provide a high degree already a difficult task for IT professionals. Most of of security and a the devices are stationary and most of the tools help pinpoint a problem to a specific physical loca- greater level of centralized control than other wire- tion. Mobile devices only increase the trouble- less systems, and it also means that the workload shooting complexity for IT professionals since and learning curve of the information manager is there is no physical connection and difficult net- reduced. All this works without modifying today's work problems can be increasingly intermittent. applications and network infrastructures. Troubleshooting errant mobile devices can make Performance: Mobile and remote users can suffer even the most experienced network troubleshooter significant performance degradation when they try armed with the most sophisticated tools still feel to adopt technologies that were implemented for like a novice. stationary systems. NetMotion enhances the exist- As IT resources are spread thinner and thinner, ing network protocol implementations to deal with companies need to consider how this additional the vagaries of mobile networking. It facilitates the load can be added onto an already overworked operation over intermittent or "bandwidth-chal- staff. No wonder this is one of the major barriers lenged" links by sharing historical information that organizations must overcome when deploying (network latency, round-trip time, etc.) among all wireless communications technologies. transport-level sessions. This sharing of informa- tion, along with other advanced algorithms, works NetMotion: The Solution to reduce the transmission of "gratuitous" data. In the end, transmission times may be reduced, since The members of the NetMotion Wireless develop- less data is being sent. This saves valuable time, ment team came from WRQ, a company with a 19- enhances the user's experience, and can increase year history of solving complex problems for the IT the network's performance. Again, all working professional. This breakthrough technology lever- without modification to today's applications and ages their experience with data access and pro- network infrastructures. vides the core technology for removing several barriers standing in the way Application persistence: Intermittent network connectivity can wreak havoc on mobile applica- of a truly mobile work force. Using a client-server tions for many reasons. With NetMotion, network relationship, it solves the difficulties for using application sessions aren't terminated even when: today's applications and technologies over today's existing network infrastructures. Furthermore, · a mobile device suspends operation; NetMotion is designed to maintain compatibility · a user disconnects or removes the wireless with standards as newer networking technologies modem from the mobile device; are developed. Here is a quick overview of how NetMotion addresses each wireless WAN limita- · or a device temporarily moves out of the cover- tion. age area. Security: Mobile and remote access over public or NetMotion eliminates lost user time—and user broadcast media can compromise network secu- frustration. NetMotion maintains the state of each rity. Even when the wireless data network encrypts user's applications on the network when the the data over the initial link, data traveling over mobile device is out of coverage, or has been sus- any other public medium, such as the Internet, is pended to prolong battery life. Once back in con- still susceptible. With NetMotion, the IT profes- tact with the network, applications seamlessly sional can be confident that each user, not just the resume where they left off. NetMotion manages device, is authenticated by the corporate network. the intricacies of wireless and mobile computing All transmissions are then optionally encrypted without requiring modification of today's applica- using industry-standard DES (56-bit or triple-DES) tions and network infrastructures. or the AES candidate TwoFish (a 128-bit key algo-

5 Roaming: Wandering out of range or between net- deployment burden. Since the NetMotion Mobility work segments confuses applications and protocol Server can be aware of every session that mobile stacks. Most wireless users today feel that they are devices establish, IT managers can determine the using "bleeding edge" technology, so they accept status of each individual device from one location. frequent disruptions in service because they seem NetMotion management and administration ser- to be a fact of life. NetMotion's advanced roaming vices include applying policies at a user or group algorithms allow users to roam—not just from one level, statistical tracking of behaviors on the sys- network interconnect to another, but across net- tem, traffic studies, and system troubleshooting. work segments, and even to different networks altogether without disconnecting. NetMotion users NetMotion replaces no standard operating system don't have to restart their machines to obtain a new components. Currently it can be deployed on any address. Users maintain application persistence standard wireless device using Windows 9x, Win- even when they cross an IP subnet boundary. dows CE, or Pocket PC (support for other plat- Employing its client-server architecture, the Net- forms is under development). Users and IT Motion server maintains the state of each mobile professionals have familiar and existing interfaces device and handles the complex session manage- and tools to work with. Using these familiar inter- faces reduces help desk calls because there is little ment required for continuous connections to the or no learning curve. Because it uses these stan- network-based applications. When a mobile device dard components and operates only on the appli- becomes unreachable because it suspends opera- cation's data, NetMotion seamlessly and securely tion, moves out of coverage, or changes its current operates over and through existing policy-enforc- "point of presence" address (roaming), the server ing equipment such as firewalls and network maintains the connection to the network peer by address translators (NATs). As long as frames can acknowledging receipt of data and queuing be routed between the NetMotion Server and the requests. Once the mobile node and the NetMotion mobile device, NetMotion requires no modifica- server are in contact again, the state of each exist- tions to applications and network infrastructures. ing connection is resynchronized, thus providing continuous network computing—all without mod- Considerations and Questions to Ask ification to applications and network infrastruc- When seeking a mobile/wireless WAN/LAN solu- tures. tion, it is important to ask several questions that Standard off-the-shelf applications: In most cases, cover how the deployment affects an organization. customization of an application is not a viable How does it affect user productivity? What impact solution, especially when the company does not does it have on network security and performance? own the code. With NetMotion, there is no need to How will my staff manage the access of these modify or recompile internally developed or off- devices? Other issues to consider are: the-shelf applications to give wireless users access 1. How long does it typically take to deploy the to mission-critical information. The same applica- wireless solution? tions users find valuable at their desktops can be easily deployed, as long as there are no applicable 2. Does the WWAN solution increase or lessen the policy or bandwidth requirement limitations. In impact on the IT staff? general, if there is a way to forward IP datagrams 3. Does the WWAN solution enable access to stan- between the corresponding nodes, NetMotion and dard business applications or must applications the "off-the-shelf" application can be seamlessly be customized? deployed. With NetMotion's compression and per- formance enhancing algorithms, the performance 4. Does the WWAN solution handle roaming? of the application may even increase. Again, all How does it handle dropped connections? without modification to applications and network 5. Does the WWAN solution include user level infrastructures. authentication to the network? Centralized management and efficient use of IT 6. What encryption standards are used? resources: NetMotion's centralized administration provides the ability to track and control device and 7. Does the WWAN solution replace standard system performance. Having one central reposi- operating system components? tory to manage mobile devices, no matter how they are connected, significantly reduces the

6 8. Does the WWAN solution work with standard network monitoring and protection tools? 9. Does the WWAN solution work through the net- work without requiring network modifications? Conclusion

If the wireless solution is doing its job, no one should know it's there. For business professionals this means getting the right data whenever and wherever they need it. It means secure access to important information stored on their content-rich networks and the ability to make the necessary, informed decisions—all the things that they can normally do from their desks. Mobile users want real-time, continuous access to the applications and data they use every day. For IT professionals, it means finding a solution that offers users what they need but has the least impact on resources for deployment, administration, and management. NetMotion is the right solution for tomorrow's net- working problems, today.

NetMotion Wireless, Inc. 1100 Dexter Ave N, Seattle, WA 98109 Tel. 206.691.5500 www.netmotionwireless.com Copyright © 2001 NetMotion Wireless, Inc. All rights reserved. NetMotion is a trademark of NetMotion Wireless, Inc. Patents Pending. WP-WWAN-051101-BW