Market Overview

The ideal situation of universal-coverage wireless broadband is not here, and may never be achieved. In any case, it will not always be convenient or economical to use 3G or (eventually) 4G wireless in all mobile working situations. Today's wireless technologies provide a patchwork of connectivity that can do different jobs in different situations, so you'll probably end up deploying a selection. Here's a tour of what's available.

There are three broad divisions into which wireless technologies can be grouped: PANs (Personal Area Networks) that provide short-range connectivity; LANs (Local Area Networks) that provide connectivity at the scale of local offices or public hot-spots; and WANs (Wide Area Networks), which -- as the name suggests -- span wide geographical zones. All current high-speed radio data networks are inherently short range, so the difference between LANs and WANs is more a question of what services are supported rather than any particular technical difference.

When evaluating any wireless system, be sure to consider upfront and ongoing costs (which can be difficult to predict accurately unless explicit promises are extracted from service providers) as well as security, compatibility with third-party service providers (especially in different territories) and the roadmap for future enhancements.

Wireless PANs

Wireless PANs are suitable for the area immediately around the desk or within the vicinity of the mobile worker. The most common current example of a PAN technology is Bluetooth, although infrared can also be thought of as a PAN. In the future, ZigBee and ultrawideband (UWB) will add some quite different options to the mix.

Infrared is the longest-serving wireless technology of them all. Its range is limited and uniquely it requires a 'line of sight' between the receiving and transmitting devices. Household remote controls use infrared. It is also built into many notebooks, handhelds and mobile phones, and is an option for connecting portable equipment to dial-up connectivity. Infrared is also used to 'beam' data between handhelds, and to link portable equipment to printers. It's not very reliable, not very fast and not very desirable. Use it if nothing else is available.

Bluetooth comes in three flavours -- Class 1, Class 2 and Class 3 -- offering theoretical maximum ranges of 100, 30 and 10 metres respectively. The 1mW Class 3 Bluetooth with 10m range is the most common, although the achievable range in any environment can be reduced by factors like other nearby wireless services, plus walls, ceilings, furniture or people between the network nodes. Bluetooth shares the 2.4GHz band with 802.11b/g wireless LANs and ZigBee.

Bluetooth has now reached version 2.0, which has an Enhanced Data Rate of 2.1Mbps, compared to the 723.1Kbps of version 1.x, with which it is backwards-compatible.

Bluetooth is integrated into many notebooks and handhelds, and quite a few mobile phones. If it's not present, it can be added via a USB adapter or an SD card (the latter is appropriate for handhelds, which lack support for USB Bluetooth adapters). Bluetooth adapters are also available that work over serial and other more obscure interfaces, so you may be able to wirelessly connect some legacy devices.

Bluetooth is designed for short-range cable-replacement applications. Examples include using a mobile phone as a modem for a notebook computer, linking a mobile phone to a handsfree headset, or a handheld to a GPS receiver, and sending data to a printer.

ZigBee is a medium-range, low-power and low-speed network designed primarily for industrial and domestic control. It has yet to be widely deployed, but is expected to make its first appearance in IT in peripherals such as keyboards, mice and remote controls. It is mentioned here for its potential to cause and be caused interference with other systems such as 802.11b/g and Bluetooth, with which it shares the 2.4GHz band.

Ultrawideband is the newest radio technology to enter service. Still under development, it is low range, low power and very high speed. It is not confined to any particular band, but spreads its signal over many gigahertz, relying on the extreme spread and very low power to avoid interfering with those other services with which it collides. Specifications are not finalised, but it will probably offer up to around 400Mbps within around five to ten metres and will first come to light in consumer electronics as a replacement for video and audio wired connections. IT use is expected to include automated backup, high-bandwidth links for synchronisation of large data sets and storage connectivity applications.

Wireless LANs

Wireless LANs are appropriate for communication over office-, home- or campus-sized areas. They are promoted by the Wi-Fi Alliance, Wi-Fi being a generic name for a collection of WLAN standards that vary in data transfer speed and range.

Wi-Fi also provides public access to the Internet in locations such as transport nodes (airports, railway stations), city hotels and cafés, and even local areas within towns or cities. There is a mix of free and charged-for business models for access to Wi-Fi services. You can find a map of UK Wi-Fi 'hot spots' here.

The most common varieties of Wi-Fi are 802.11b and 802.11g. These both use the 2.4GHz band but have theoretical data rates of up to 11Mbps and 54Mbps respectively (typical real-world speeds tend to be between a quarter and a half of these figures due to environmental effects and data correction). To get the best from 802.11g, all nodes should be at that speed, as 802.11b traffic on the same network may reduce the overall data transfer speed. Similarly, care should be taken if Bluetooth or ZigBee -- which also use the 2.4GHz band -- are deployed in the same area.

Another 54Mbps variant, 802.11a, is also available, but is not compatible with the b and g standards as it uses a different (5GHz) radio band. Although 802.11a is uncommon and has a slightly shorter range than 802.11b/g, the quiet 5GHz band makes it a good choice in areas that are already densely populated with wireless LANs.

The future for Wi-Fi is 802.11n. This will offer a data throughput of at least 100Mbps -- some 10 times faster than 802.11b, and with a much greater range. Certified 802.11n products should start to appear in 2007, although 'pre-N' hardware is already available. This offers most of the promised range and speed advantages, but may not be upgradeable to the official standard when this is ratified.

Wireless WANs

Wireless WANs use the mobile technologies that form the cellular networks. The most widespread of these are '2G' GSM (Global System for Mobile communications) for voice and '2.5G' GPRS (General Packet Radio Services) for 'always on' data services at a theoretical maximum of 171.2Kbps (around 56Kbps in practice). Other 2.5G technologies are HSCSD (High Speed Circuit Switched Data) and EDGE (Enhanced Data rates for GSM Evolution), although neither are as widely available as GPRS. EDGE can deliver between two and three times the data throughput of GPRS, but is not currently deployed by any of the UK's mobile networks.

The 2G/2.5G networks are slowly being eclipsed by 3G, which offers even faster data rates -- currently the maximum is 384Kbps in the UK. Business access to 3G services is offered by the four main UK operators -- O2, Orange, T-Mobile and Vodafone -- via 3G data cards for notebooks. O2, Orange, Vodafone and 3 offer handset-based 3G services, and many of these phones can be used as 3G modems for a notebook via a Bluetooth connection. Note, though, that 3G network coverage is by no means universal throughout the UK, and when 3G coverage is not available data services fall back to a slower GPRS connection.

Future, faster, wireless WAN technologies include HSPDA (High Speed Packet Downlink Access), a 3G enhancement dubbed 'Super 3G' that will deliver around 1.8Mbps initially and up to 14.4Mbps eventually. O2 has recently begun an HSPDA trial in the Isle of Man. Then there's Mobile WiMAX (802.16e), a mobile version (currently still under development) of the fixed WiMAX (802.16a) wireless technology that will serve 'metropolitan area networks' (MANs) and provide 'last-mile' broadband connectivity in remote rural areas. Beyond that, there's 4G, for which a number of technologies are still competing and whose final shape in the UK and Europe (and elsewhere) is still to emerge.

When choosing an operating system for a mobile device, you need to consider a number of factors. These include system requirements, user interface, device support, software availability, developer-friendliness, power management, connectivity and security. Here's a tour of the main operating systems available for notebooks, handhelds and smartphones.

NOTEBOOK OPERATING SYSTEMS

Windows XP

Windows XP is the standard office worker’s operating system, and as such is likely to come preinstalled on any notebook PCs you buy unless you specify otherwise. XP has relatively high-end system requirements (see below), but offers a familiar user interface, good device support, plenty of available software (including a wide range of bundled utilities and applications), a huge developer community, decent (ACPI-based) power management and good connectivity including Bluetooth support, good Wi-Fi management and a built-in VPN client.

XP Professional also offers a 'remote desktop' feature that allows mobile users to access their office-based desktop computer from the field. Another useful XP Pro feature for mobile users is the Encrypting File System (EFS), which ensures that sensitive data cannot be read even if a notebook is stolen and the hard disk accessed. However, the biggest drawback with Windows XP remains security, even following Service Pack 2, which was largely designed to address this issue.

Windows XP Tablet PC Edition is designed specifically for Tablet PCs. It includes all the features of Windows XP, and adds support for pen-based input and portrait as well as landscape screen orientation. Extra bundled applications such as Windows Journal for organising handwritten notes and the Tablet PC Input Panel with its built-in handwriting recognition are designed to make the most of keyboard-free operation.

Windows XP is due to be superseded by Windows Vista (formerly codenamed Longhorn) in 2006. A beta version for developers and IT professionals is now available.

Windows XP system requirements  PC with 233MHz x86 CPU, 64MB RAM, 1.8GB free hard disk space, CD or DVD drive for installation

Mac OS X

Despite OS X Tiger's demanding system requirements (see below), Apple's PowerBooks are reasonably portable, if expensive, notebooks. The operating system, which is based on BSD Unix, is lauded for its user-friendly Aqua interface, Spotlight metadata-based search tool and auto-updating Smart Folders, Dashboard with easy access to useful applets (Widgets) and Automator for making light work of repetitive tasks. You get plenty of bundled software, including iChat (H.264-based videoconferencing) and Safari RSS (Web browser). Malware is much less of an issue with Mac OS X than it is with the high-visibility Windows XP, and security features include a personal firewall, an auto-update facility, file and disk image encryption and permanent file deletion.

The next upgrade to Mac OS X, version 10.5 Leopard, is due at the end of 2006, and will support both PowerPC- and Intel-based Macintoshes.

Mac OS X system requirements  Macintosh with PowerPC G3 or G4 CPU, 256MB RAM, 3GB free hard disk space (4GB with developer tools), DVD drive for installation

Linux

In the past, the difficulty of installing Linux, patchy device support and opaque user interfaces kept it from widespread acceptance. In the notebook arena, power management was also an issue. However, progress has been made in all these areas, and there's now little reason to discount Linux from your mobile working plans, particularly if you opt for one of the leading distributions with a good technical support infrastructure.

Typical Linux system requirements (Novell Linux Desktop 9)  266MHz Pentium II or higher, or any AMD64 or Intel EM64T CPU; 128MB RAM (256MB recommended), 800MB available hard disk space

HANDHELD & SMARTPHONE OPERATING SYSTEMS

Windows Mobile

Windows Mobile comes with cut-down versions of the familiar Office applications – Outlook, Word, Excel, plus Internet Explorer – along with a range of other productivity- and connectivity-related programs, including software to manage Bluetooth and Wi-Fi connections, plus Terminal Services and VPN clients. There is a healthy Windows Mobile developer community, and plenty of third-party software available. Check ZDNet's downloads channel for a wide range of Windows Mobile software for handhelds and smartphones.

An upgrade to the OS, Windows Mobile 5.0, was announced in May, but is not expected to appear in devices for a few months. Among the key features of Windows Mobile 5 is the ability to store user data in persistent ROM rather than RAM (which is lost if the battery is drained) and to mount a handheld as a USB Mass Storage Device for quick and easy data transfer to and from a host PC. Recently, Microsoft announced a Messaging and Security Feature Pack for Windows Mobile 5.0, which takes advantage of forthcoming wireless features in Exchange Server 2003 Service Pack 2.

In shipping handhelds and smartphones, you'll find the second editions of Windows Mobile 2003 for Pocket PC and Windows Mobile 2003 for Smartphone. There's also a Phone Edition of the Pocket PC OS; this is designed for connected handhelds that incorporate a mobile phone such as O2's xda IIi (in the new Windows Mobile 5, the Phone Edition is incorporated into the standard OS).

Windows Mobile 5 system requirements  ARM-based CPU, 32MB Flash ROM, 64MB SDRAM

Palm OS

All current Palm OS-based devices run some variant of Palm OS 5 -- even the Treo 650, which is a SIM-equipped handheld/mobile phone combo. Palm OS 6.1 has yet to appear in any shipping product.

Palm OS 5 includes a core bundle of PIM, productivity and connectivity applications, to which hardware manufacturers generally add their own choice of third-party software. PalmSource claims that there are 20,000 Palm OS applications available and 400,000 developers, licensees and strategic partners for the platform. Check ZDNet's Downloads channel for a wide range of Palm OS software.

Palm recently licensed from Microsoft the software tools necessary for direct OTA data synchronisation with Microsoft Exchange Server 2003 (SP2).

Palm OS 5 (Garnet) system requirements  ARM-based CPU, 4MB Flash ROM, 1MB SDRAM

Symbian OS

The Series 80 Symbian platform is available in Nokia's 9300 Smartphone and 9500 Communicator, both of which are clamshell-style mobile phone/handhelds with small built-in keyboards and letter-box-style screens. These more powerful devices come with and can run a wider range of applications than Series 60 phones.

Finally, with the UIQ interface, Symbian is available in the UK in a small number of handsets from Sony Ericsson and Motorola.

Like Palm, Symbian recently licensed from Microsoft the software tools necessary for direct OTA data synchronisation with Microsoft Exchange Server 2003 (SP2).

Other mobile operating systems

The RIM operating system appears mainly in Research In Motion's popular BlackBerry devices, although BlackBerry functionality is licensed to third parties under the BlackBerry Built-In and BlackBerry Connect schemes.

Designed primarily with the aim of providing 'push' access to mobile email, BlackBerry handhelds and smartphones also cater for PIM data, and can run third-party software. However, they are not as sophisticated as other mobile devices either in terms of their hardware capabilities or the amount of third-party software available.

Linux is also available on a few handhelds, notably in Sharp's Zaurus range. Nokia also recently announced a Linux-based handheld, the 770 Internet Tablet. Finally, as mentioned above, PalmSource's purchase of China MobileSoft suggests that Linux-based smartphones may be available from the company's hardware partners in due course.

Mobile computing devices are all about trade-offs. If you need lots of computing power, a big screen and a comfortable keyboard, for example, then with today's technology you're going to have to carry a fairly bulky and weighty system -- especially if you want decent battery life as well. Lighter, more compact or longer-lasting devices have to make compromises along the way: hardware designers and manufacturers produce a range of solutions, and companies need to choose the ones that best fit their businesses carefully. Here's an outline of the main classes of mobile device.

Notebooks & Tablet PCs

Notebook computers are ideal for mobile knowledge workers who need a reasonably large screen and a keyboard in order to create documents or presentations while away from the office. In terms of computing power and functionality, higher-end notebooks can now rival desktop computers, although they tend to cost more and are harder to upgrade. Built-in wireless networking is pretty much ubiquitous in all classes of notebooks these days, but can easily be added via a PC Card or USB adapter if absent.

Traditional clamshell notebooks can be divided into four weight-based classes: ultraportables (<2kg), thin-and-lights="" (2-3kg),="" mainstream="" systems="" (3-4kg)="" and="" desktop="" replacements="" (="">4kg). Most mobile workers will be interested in ultraportable or thin-and-light notebooks, although those who travel regularly by car or who need a more powerful and functional system for their work may choose a mainstream or desktop replacement system. The table below shows the main features of each type of notebook:

Battery life for a typical thin-and-light notebook will be around 4 hours, which means a recharge or carrying a spare battery if you need a full 8-hour working day's worth of mobile uptime. Ultraportables often use smaller-capacity standard batteries in a quest for low weight, but generally support an optional (heavier) extended-life battery.

Tablet PCs are a special case, characterised by their ability to accept input from a stylus. This allows for on-screen drawing and handwriting recognition, which is built into the Windows XP Tablet PC Edition operating system.

There are two types of Tablet PC -- ‘slate’ and ‘convertible’. Slate-style Tablet PCs lack a built-in keyboard and are designed primarily for pen-based input, although you can usually add an external keyboard or a keyboard-equipped docking unit. Slates are most suitable for vertical market sectors where users need to stand or walk about, making keyboard input impractical. Examples include healthcare workers, warehouse or inventory management personnel and some customer-facing activities.

Convertible Tablet PCs look like conventional notebooks, but their screens swivel to lie flat on the keyboard, face up. In this configuration they can be used like a (rather bulky) slate device, while their keyboard also allows for standard clamshell notebook-style working.

Slate-style (left) and convertible (right) Tablet PCs, from Motion Computing
and Lenovo respectively.

Handhelds

When handheld computers were called PDAs, their primary purpose was to manage personal information such as contacts, appointments, tasks and notes. These standalone devices -- which synchronise with a host computer via USB or infrared -- are fast becoming obsolete. The modern breed of wireless-connected handheld lets you surf the Web, access corporate networks, check and send email and work on documents, and can be a productive business tool.

Handhelds are suitable for mobile workers who need to store moderate amounts of data: internal memory can be expanded using Flash cards -- generally SD or CompactFlash units. One handheld, the Palm LifeDrive, has a 4GB hard disk -- something that's likely to become common on high-end devices. Handhelds have touch-sensitive screens and are particularly suitable for forms-based data gathering. Software-based keyboards and built-in handwriting recognition allow for limited data input, while external keyboards can be added if you need to create longer documents.

Handhelds come in several varieties. Some 'connected' handhelds incorporate GSM/GPRS mobile phones for voice calls and wide-area connectivity. Some have tiny keyboards built in to make messaging and (short) document creation easier, while others rely on pen-based input alone. Some even have integrated GPS receivers, making them convenient and portable navigation devices. Personal- and local-area connectivity is commonly built in, via Bluetooth and Wi-Fi respectively -- if absent, either of these features can be added via an expansion card (usually an SD Card); 3G connectivity has yet to be integrated into a handheld, but cannot be far away. The two main handheld operating systems are Windows Mobile and Palm OS. Here's a summary of the key features of the main types of handhelds:

As far as battery life is concerned, you can expect somewhere between 4 and 8 hours' continuous use when simply running applications, although heavy use of Wi-Fi, mobile phone and/or GPS will reduce this. If you need a full day's mobile uptime, look for a model with a user-replaceable battery so you can swap in a spare as required.

Smartphones

Smartphones are voice-centric devices that can share PIM data and, in some cases, files with a desktop computer or -- with appropriate back-end software -- over the air with email and groupware servers. They generally resemble somewhat bulky mobile phones and usually offer Bluetooth for short-range wireless connectivity. Wi-Fi is rare for this form factor (limited, in fact, to Nokia's 9500 Communicator), although this may change before long.

The main smartphone operating systems are Windows Mobile, Symbian and the RIM OS found in BlackBerry devices. Palm OS and Linux are also in the picture. One of the most eagerly awaited smartphones is the recently announced Motorola Q, a Windows Mobile 5.0-based smartphone, which is due in the first quarter of 2006.

Motorola's Q, due early in 2006,
will be among the first Windows
Mobile 5.0 smartphones.

Smartphones are suitable for mobile workers who need access to basic PIM data, some files and, of course, voice communications. Although it is possible to view and edit spreadsheets, Web sites or other graphics-rich documents on smartphones, their small screens and cramped keypads are not well suited to this type of activity. When linked to a notebook or handheld via a cable, infrared or Bluetooth, many smartphones can be used as modems to provide Internet connectivity.

Other mobile devices

Some working conditions are too demanding for standard mobile devices, and in these situations companies can opt for specialist ruggedised devices. More information on ruggedisation and the standards in this area can be found here. Examples of rugged notebooks include Panasonic's ToughBook range, although there are many smaller specialist vendors.

Also useful for many mobile workers is the standalone GPS navigation system such as the Tom Tom GO range. The latest Tom Tom GO models can also be used as a handsfree voice kit in conjunction with a Bluetooth phone.

Mobile device security

A number of measures can be employed to keep mobile devices secure. These should not be considered as mutually exclusive.

You should consider two aspects of security: access to the machine itself, and authentication on your network. Network access can be both machine-specific and user-specific.

Access to the machine itself can be controlled in a number of ways. Devices such as some ThinkPad notebooks and a couple of handhelds from Hewlett-Packard have built-in fingerprint readers. Smartcard readers are also available for many notebooks. A notebook can be set up to boot only when it has received biometric or smartcard authentication, to use passwords when the operating system runs, and to encrypt specific files.

Device security is built into most handhelds in the form of alphanumeric passwords. User authentication systems on handhelds can also be augmented by software-based systems that include signature recognition. Some mobile devices with wide-area wireless connectivity can be managed remotely, with security options including remote device locking and remote device reformatting.

As we have seen, the mobile market includes a diversity of wireless connectivity technologies, platforms and devices. All this poses a challenge to IT managers when it comes to delivering the applications that mobile workers require in order to be productive on the move.

Notebooks have the processing power and storage to carry a full set of business applications and large amounts of data, and are therefore a more straightforward case. When notebook users are offline they can work on documents, prepare emails, presentations and so on; when a secure Internet connection is available, they can synchronise with corporate servers and run any applications that require real-time connectivity.

With an Internet connection, the mobile applications you can run depend on the bandwidth available. Low/medium-bandwidth applications include instant messaging, email (without large attachments), groupware (which includes PIM data such as contact, calendar and task management), CRM (customer relationship management) software and access to corporate intranets or extranets.

If you want to carry out more demanding activities like Web conferencing, application sharing or voice over IP (VoIP), or download large amounts of information from corporate databases, then you'll need significant bandwidth -- certainly faster than GPRS. Given the current geographical patchiness of high-bandwidth connectivity, there will only be certain places where mobile workers will be able to run these more advanced applications -- at a Wi-Fi hot spot, a client's office or at home, for example, or in an area with good 3G coverage.

Mobile application & wireless email gateways

Moving from notebooks to handhelds and smartphones, not only is there considerably less processing power, memory and storage available, but also the range of platforms, devices and capabilities is much greater. This makes the IT management problem potentially much harder. However, there's a rapidly developing class of client/server middleware product -- the mobile application gateway -- that can deliver managed access to corporate resources from such devices.

The most widely used type of mobile application gateway is the wireless email gateway, typified by products like BlackBerry Enterprise Server, GoodLink Wireless Messaging and Visto Mobile Enterprise Server. These products, and others like them, generally sit behind the corporate firewall (although some can also be hosted by an application service provider or ASP), integrate with some or all of the major email/groupware servers (Microsoft Exchange, IBM/Lotus Domino and Novell GroupWise), offer secure 'push' email functionality to a variety of mobile client platforms, and support sophisticated management features like over-the-air provisioning and remote data wiping.

Good Technology's GoodLink provides wireless access
to Microsoft Exchange email on Windows Mobile
(pictured here) and Palm OS devices.

A trend for many of these wireless email gateways is to provide hooks for other business applications such as CRM and ERP (Enterprise Resource Planning) systems, transforming them into fully fledged mobile application gateways, similar to products like IBM WebSphere Everyplace Access. More sophisticated solutions use mobile VPNs (Virtual Private Networks) like IBM’s WebSphere Everyplace Connection Manager to support seamless roaming between different wireless and wired networks without interrupting applications.

Direct email server access

Companies that cannot justify the expense of a third-party wireless email gateway may find that the mobile capabilities of their existing email servers are sufficient for their purposes. If your business runs Microsoft Exchange Server 2003, for example, you can use ActiveSync to synchronise email and other PIM data on a Windows Mobile handheld or smartphone directly over a wireless Internet connection. Service Pack 2 for Exchange Server 2003, due later this year, will boost the manageability of the wireless features, adding capabilities such as push email, device passwords and remote data wiping. Microsoft has recently licensed its ActiveSync technology to both Palm and Symbian, which greatly expands the range of mobile devices that can access Exchange Server 2003 SP2.

IBM/Lotus Domino sites can employ IBM WebSphere Everyplace Access to synchronise email and PIM data over the air on a variety of mobile client platforms, although this solution doesn't currently employ push technology. Finally, if your company uses Novell GroupWise, then the bundled WebAccess functionality supports wireless access to email and PIM data via a connected mobile device's browser.