Wireless USB is a wireless technology which enables the high speed computer peripheral interface, USBs. It is a wire replacement of existing USB technology using a Multi Band Orthogonal Frequency Division Multiplexing radio technique. Wireless USB is a logical bus that supports data exchange between a host device(typically a PC ) and a wide range of simultaneously accessible peripherals. The attached peripherals share bandwidth through a host- scheduled, TDMA-based protocol. The bus allows peripherals to be attached, configured, used, and detached while the host and other peripherals are in operation. Security definitions are provided to as sure secure associations between hosts and devices, and to assure private communication. Wireless USB connects USB devices with the USB host using a ‘hub and spoke’ model. The Wireless USB host is the ‘hub ” at the center, and each device sits at the end of a ’spoke’. E ach ’ spoke ‘ is a point-to-point connection between the host and device. Wireless USB hosts can support up to 127 devices.
INTRODUCTION
Universal serial bus[USB] technology has made it easier to connect peripherals to PCs than prior methods, such as serial and parallel ports. USB lets users attach peripherals and other devices-such as digital cameras, game controllers, hard drives, printers, and scanners-without having to install individual drivers or use expansion cards, all without rebooting the computer. However, USB requires connections via cables, which can become a jumble when many devices are involved. And the cables limit the distance over which users can connect devices. To address this issue, a number of companies-including Alereo, Belkin International, D-Link, Fujits, Gemtek Technology, Hewlett-Packard, Icron Technologies, Intel, Lenovo, LSI Corp., Realtek Semiconductor, Samsung, Staccato Communications, Synopsys, and Wisair- are beginning to release products based on wireless USB (WUSB). “There is significant interest among both computer and consumer- electronic vendors to move from wired to wireless peripheral connections,”
The use of consumer electronics with computers in home-entertainment systems has created a market for WUSB products, which offer easier implementation and communication of multimedia between devices than wired USB provides, Moreover, the technology would let users move around with connected mobile devices beyond the reach of cables.
The initial WUSB products will be dongles and hubs, but vendors will release computers and devices with built-in WUSB capabilities later this year, Huang predicted. Proponents believe large-scale WUSB sales are just over the horizon. As Figure 1 shows, In-Stat estimates there will be 4 billion USB-enabled devices worldwide by 2011, with 503 million, or 12.6 percent, using WUSB. This year, In-Stat predicts, out of 2.5 billion USB devices, only 3 million, or 0.1 percent, will be WUSB-enabled.
Design Considerations
There are several architectural considerations in developing WUSB. In addition to providing wireless connectivity, WUSB must be backwards compatible with wired USB and provide a bridge to wired USB devices. Also, the host and solutions will need to enable the exchange of data between clusters or devices not related to the same host. Low-cost implementation of WUSB will also be important to the successful integration of the technology. Implementation will follow the wired USB connectivity models as closely as possible to reduce development time and to preserve the low-cost, easy-to-use model, which has become pervasive in the PC industry.
FEATURES OF UWB:
• Scaleable speeds up over 1 Gbps
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. The trend toward convenient wireless distribution of digital information provides an opportunity to introduce a single, standard wireless interconnect capable of supporting usage models across all three environments.
The CE environment will have high-performance wireless interface expectations. Consumer usage models will center on streaming media distribution that typically uses compression algorithms. The performance objective is to ensure a high quality of service is maintained to meet typical consumer entertainment expectations. Typical video delivery with standard SDTV/DVD will consume between 3 and 7 Mbps while HDTV will use between 19 and 24 Mbps. A point distribution technology like wireless USB with an effective bandwidth of 480 Mbps could manage multiple HDTV streams. Host buffering could enable a network backbone to effectively distribute content to all distribution hosts, enhancing the quality experience for allusers.
Business applications for WUSB include a variety of different usage possibilities. Common devices such as printers, scanners, harddrives, and projectors could all be used in wireless scenarios. These devices would function the same way as if they were using wired USB, but without all the cables. Office services on the corporate network could migrate to WUSB and benefit from faster performance than shared network devices offer.WUSB also supports dual-role devices(DRDs), which in addition to being a WUSB device, can function as a host with limited capabilities. For example, a digital camera could act as a device when connected to a computer and as a host when transferring pictures directly to a printer.
CONCLUSION
As discussed above, Wireless USB is a technically-superior interface technology but its advantages are the result of significantly greater complexity when compared to wired USB. Given today’s demanding customers and competing interface technologies, we believe that manufacturers can only ensure market acceptance by delivering robust Wireless USB performance in their initial products.
The quality of a Wireless USB implementation will depend on the ability to successfully balance high throughput and power. After achieving basic operation with early prototypes, these are key success factors which developers will need to address to fine-tune product performance. For example, it is entirely conceivable that a poor Wireless USB implementation will repeatedly retransmit as a result of data errors, slowing down its throughput and wasting valuable battery power. As concluding part we can say that WUSB since be will designed and has got good support more products need to be improved.
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