“NETWORKING SYSTEMS”
“WIRELESS USB”
-An Analysis of networking systems Implementation using Universal Serial Bus.
Abstract:
Universal Serial Bus (USB) is a new personal computer (PC) interconnect that can support simultaneous attachment of multiple devices in which the wireless technology has been recently introduced. Human Interface Devices (HID) class device developers wish to provide wireless versions of their products and take advantage of the USB features. This paper presents an analysis of the issues related to implementing Universal Serial Bus (USB) without cables. In general the issues raised here apply to any single USB device that presents multiple devices to the system. The premise of this paper is that there should be no difference between a wireless and a wired device. The function of the Wireless USB is to provide transparent operation. This paper analyzes the requirements that a wireless device must meet to emulate a device to a USB host over a wireless link.
Overview:
The Universal Serial Bus (USB), with one billion units in the installed base, is the most successful interface in PC history. Wireless USB will build on the success of wired USB, bringing USB technology into the wireless future. Usage will be targeted at PCs and PC peripherals, consumer electronics and mobile devices. To maintain the same usage and architecture as wired USB, the Wireless USB specification is being defined as a high-speed host-to device connection. This will enable an easy migration path for today’s wired USB solutions.
Each of these portable devices has a need to connect to other devices such as PCs or stationary consumer electronics products, such as stereos, HDTVs, video recorders, entertainment PCs, or the like. All these devices would benefit from the ability to connect without cables. Think, for instance, about the number of devices in your home and the tangle of wires between them. Wireless USB would eliminate these wires and enable devices to wirelessly connect to each other.
Introduction:
Imagine if all the devices in a home or office -- such as printer, scanner, external hard drive, and digital camera -- could be connected to your PC without any wires. Imagine if all the components for an entire home entertainment center could be set up and connected without a single wire. Imagine if digital pictures could be transferred to a photo printer for instant printing without the need for a cable. These are just some of the possible scenarios for high-speed wireless USB (WUSB) connectivity, the latest technology developed to bring even greater convenience and mobility to devices.
With the growing use of digital media in the PC, consumer electronic (CE) and mobile communication environments, a common standard interconnect is needed to support the on-going convergence of these environments. Universal serial bus (USB) technology has been a popular connection type for PCs and it's migrating into consumer electronic (CE) and mobile devices. Now this high-speed and effective connection interface is unwiring to provide the functionality of wired USB without the burden of cables.
WIRELESS USB- An analysis:
Wireless USB is the new wireless extension to USB that combines the speed and security of wired technology with the ease-of-use of wireless technology. Wireless connectivity has enabled a mobile lifestyle filled with conveniences for mobile computing users. Wireless USB will support robust high-speed wireless connectivity by utilizing the common Wireless Media MB-OFDM Ultra-wideband (UWB) radio platform.
For the past decades, connection between the host and other devices is a critical issue.Introduction of wireless USB (W-USB) generates lots of excitement within the UWB community. The good news is that the process on the W-USB is very simple. When wireless USB is shipped on PCs, it will motivate everyone to do the same on other devices. We expect wireless USB functionality will then penetrate the CE [consumer electronics] market. Since there is no such thing as 'wireless electricity,' alternative power sources such as batteries must be considered. Granted, wireless USB is low power and rechargeable batteries are great, but still their presence must be factored in.
· Wireless USB is the first high-speed wireless personal interconnect technology to meet the needs of multimedia consumer electronics, PC peripherals, and mobile devices.
· Wireless USB will preserve the functionality of wired USB while also unwiring the cable connection and providing enhanced support for streaming media CE
devices and peripherals.
Wireless USB protocol is the Micro-scheduled Management Commands which are used to help devices discover information about a Wireless USB cluster.
Technology Requirements:
Topology:
The fundamental relationship in Wireless USB is the “hub and spoke” topology. The host initiates all the data traffic among the devices connected to it, allotting time slots and data bandwidth to each device connected. These relationships are referred to as clusters. The connections are point-to-point and directed between the Wireless USB host and Wireless USB device. The main difference here from wired USB case is that there are no hubs present in the connection topology. The Wireless USB host can logically connect to a maximum of 127 Wireless USB devices. Wireless USB clusters co-exist within an overlapping spatial environment with minimum interference, thus allowing for a number of other Wireless USB clusters to be present within the same radio cell. In addition to providing wireless connectivity, Wireless USB will be backward compatible with wired USB and provide bridging to wired USB devices and hosts. A method will be required to enable the exchange of data between clusters or devices not related to the same host. This method may be a second-level connection between two hosts (i.e., a network) or some method of transferring data between two clusters not managed by the same host. The star topology of Wireless USB is conceptually simple while the topology of wired USB device can be a chaotic hierarchy with multiple links of differing speeds.
Connectivity:
Wireless USB technology will support the following attributes:
Simple, low-cost implementation. The implementation will follow the wired USB connectivity models as closely as possible to reduce development time and to preserve the low-cost, ease-of-use model which has become pervasive in the PC industry.
A point-to-point connection topology supporting up to 127 devices that follows a similar host-to-device architecture as used for wired USB.
High spatial capacity in small areas to enable multiple devices access to high bandwidth concurrently. Multiple channel activities will be able to occur within a given area. The topology will also support multiple clusters in the same area. The number of clusters to be supported is yet to be determined.
A dual-role model where a device can also provide limited host capabilities. This model would allow mobile devices to access services with a central host supporting the services (i.e., printers and viewers). It would also allow devices to access data outside a cluster they are connected to by creating a second cluster as a limited host.
Performance:
Wireless USB performance at launch will provide adequate bandwidth to meet the requirements of a typical user experience with wired connections. The 480 Mbps initial target bandwidth is comparable to the current wired Hi-Speed USB standard. With 480 Mbps as the initial target, the Wireless USB specification will allow for generation steps of data throughput. As the Ultra-Wideband (UWB) radio Wireless USB is based on evolves and future process technologies take shape, bandwidth could exceed 1 Gbps. The specification intends for Wireless USB to operate as a wire replacement with targeted usage models for cluster connectivity to the host and device-to-device connectivity at less than 10 meters. Wireless USB performance is targeted at 480 Mbps at 3 meters and 110 Mbps at 10 meters.
Power Management:
“WUSB supports a variety of power modes”
New in Wireless USB is a sophisticated power management scheme designed to maximize battery life. This power management scheme is totally transparent to users of wireless USB devices. WUSB devices can be placed in suspend mode and still retain the ability to wakeup the system. Radio system power (power used only by the radio) will be expected to meet the most stringent requirements, particularly where mobile and handheld battery life is important. A typical PDA uses between 250-400 mW without a radio connection. Cellular phones typically use 200-300 mW with the primary WAN radio. Adding a Wireless USB radio should not increase power requirements such that battery life would be reduced more than by existing wireless technologies employed today. Battery-powered operation requires reasonable battery life – 3 to 5 days for highly mobile devices and several months for intermittently used devices like remote controls. Wireless USB based on MultiBand OFDM Alliance (MBOA) radio will strive to meet this standard. The power target for Wireless USB radio will be less than 300 mW at introduction and drive to a target of 100 mW over time. Creative power management techniques will be used to preserve battery life. The radio, for instance, will sleep when possible and wake upon request. Power will also be conserved by stopping power-draining operations during idle periods.
Backward Compatibility:
Wireless USB is backward compatible to wired USB devices. When connecting, a Wireless USB-enabled host and devices will go through a series of verification steps. For example, the device and host will request, receive and check each other's unique identifications, and then challenge each other with connection keys. If the host and device satisfy each other's challenges, they will establish a session key that is private for that connection.
People may have several options about activating a connection. For example, to upload pictures from their camera to their PC, users could press a button on the camera, which would then connect to the host. The Wireless USB connection between device and host could be automatic. If a switched-on device is within range of the host, it will alert the user, asking if they want to connect
Ease of Use:
Like traditional USB, Wireless USB is simple to install and set up, with the additional ease that comes with a cable-free environment.
Office/Business Usage Scenarios:
Connectivity issues and other inconveniences of wired connections can hurt productivity and slow the adoption of new devices within the work environment. Users of mobile computers and PDAs particularly face connection challenges as they move from place to place and want to use printers and other devices. Wireless USB could simplify their lives while providing a time-saving, high-speed connection that enhances productivity . In this section, we give some typical scenarios of how Wireless USB could enhance connectivity in the office.
Dedicated Office Services:
Executives, managers and heavy users need faster, dedicated services their office rather than those shared on the network. With Wireless USB, devices such as inkjet and laser printers, scanners, external storage devices, and PC cameras can quickly connect and exchange data at high speed. Top Wireless USB uses will probably include simultaneous and frequent-use mass storage for data backup, printer connectivity, scanner connectivity, and PDA or cell phone synchronization.
Printing to
For office workers that are very mobile and frequent different areas of an enterprise, the option of easily printing from a mobile platform (notebook PC, PDA, cell phone, etc.)
Office A:
Removal of the docking station and all associated cables – connect to a keyboard, mouse
and monitor wirelessly, as well as to a scanner, HDD, etc.
Office B:
Business professionals that need faster and dedicated services in their office. Likely devices are printers, scanners, mass storage, keyboard, mouse and PC cameras Easily print from mobile platform (mobile PC, PDA, mobile phone) to the nearest printer or multi-function device is very attractive. With Wireless USB, a worker could simply approach the nearest printer or multi-function device and print the needed documents. This would alleviate many of the inconveniences today in finding a printer on a network
and connecting to it.
Synchronizing a PDA with a Network:
In industries such as medical, manufacturing and retail where mobile devices are becoming pervasive having wireless data synchronization ability would allow users to quickly sync with a central computer to update the information in corporate database. Wireless USB, for example, could enable medical professionals making rounds to take notes and collect data on patients via handheld or PC tablet, and then quickly sync with the network to access additional patient data/history and treatment plans.
Sharing of Peripheral Devices:
Wireless USB will enable colleagues to more easily share devices and use each other’s devices within an office environment. Easy sharing of scanners, printers, storage devices, and other possible peripherals would be possible. Exchanging large files off hard disk drives without sending them through e-mail or over the network would be possible.
Dual-role Devices:
A new class of Wireless USB dual-role devices is projected to eliminate wires in many usage scenarios and enable new uses not previously possible. These devices will offer both limited host and device capabilities, similar to that experienced with USB On-The-Go. (
Camera to Printer:
Wireless USB could enable people to wirelessly download and print digital photos to a color printer. Imagine taking Transfer digital photos from camera directly to printer Transfer raw video directly to DVDs Transfer video content to PVP for viewing while on the road Play music (MP3s) directly to speaker system in any room
Transfer data from PC to mobile phone, such as calendar, contacts, music, photos, etc. Connect PDAs to mass storage devices such as: HDD, CD-RWs, DVD-RW, Flash card readers, etc.
Digital Camcorder to Digital Display:
Instead of having to run a cable from your digital camcorder to the video and audio ports of a display device, Wireless USB would enable you to connect without wires. You could instantly share your video with friends and family.
MP3 Player to Wireless Speakers:
Many people already carry their music wherever they go. Imagine being able to connect to high quality surround sound speakers wherever you are. With Wireless USB, you could forget cables. Just hit play and listen.
Digital Content Transfer to Personal Video Player:
Wireless USB would enable hours of content to be transferred in minutes from a personal video recorder or set top box to a personal video player. You could catch up on the morning news, a movie or sitcoms wherever the day takes you.
Conclusion:
The wireless future will truly arrive once Wireless USB, along with the Common Ultra-Wideband Platform, becomes a standard part of every processor and chipset, integrated in CMOS silicon. The goal is for Wireless USB to become the wireless interconnect of choice for desktop and mobile PCs, handheld, mobile, and consumer electronic devices, allowing easy connection and data exchange at high
speeds without wires.
Summary:
As the latest iteration of USB technology, wireless USB (WUSB) will offer the same functionality as standard wired USB devices but without the cabling. The new Wireless USB Promoter Group prepares to develop the specifications that will help standardize the technology, the industry is planning products that can take advantage of the convenience and mobility that this new device interconnect will offer.
REFERENCE:
“principle of communication systems” –
“extremelyusb”- M.J.Augenstein ,A.M.Tenebaum.
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