Imagine if all the devices in a home office—such as printer, scanner, external hard drive, and digital camera—could be connected to your PC without any wires. UWB is a frequency spectrum which will help wired USB to migrate in WUSB domain. Ultra-wide band radio technology, in particular, has characteristics that matches traditional USB usage model well. UWB supports 480Mbps bandwidth with limited range of 3 meters.
WUSB: HCL APPROACH
On the basis of WUSB standard, HCL has recently developed IP cores for WUSB host controller and
device controller with UWB based MBOA MAC and PHY interface. This WUSB host and device controllers are based on the WUSB specification, MBOA MAC and PHY specifications.
Some features of HCL’s WUSB host and device controllers include:
• Support for USB Specification Revision 2.0 and WUSB
Specification Revision 1.0
• Support for AMBA AHB rev. 2.0 based processor interface
• Generates MMC packet
• AES 128 encryption/decryption
• Channel time allocation (CTA)
• CRC generation and checking
• Generates MAC header
• FCS sequence appended
• Support for MBOA PHY
interface
• 4-way authentication
• Supports UTMI interface
• De-fragments data and token, and buffers them separately
• Generates WUSB header
• Interfaces with wireless MAC
• Implements frame counter
The MBOA PHY layer encodes and decodes the data packets and transmits and receives them over the radio channel.
WUSB host and device controllers are compliant to standard UWB PHY interface, and can support 480Mbps bandwidth with limited range of 3 meters.
The WUSB host controller architecture is based on three layers: USB 2.0 host controller, scheduler, and MAC layer. Each layer is divided in multiple blocks.
The WUSB scheduler will schedule the WUSB channel with timestamps as required by MBOA MAC and also append the WUSB header.
The WUSB device controller is based on two layers, USB 2.0 device controller and MAC layer. WUSB device controller is not scheduling any packets so scheduler functionality is not required in a WUSB device controller.
CONCLUSION
Though WUSB technology is in the early stage of its evolution, it has the full potential to replace the existing USB with a wireless one. The UWB based MBOA will be supporting the radio medium in providing high data rate transfer with low energy emission. High bandwidth is the key attraction of WUSB technology.
Authors information
You can reach the authors at opsri@hcl.in
Caqption: Figure 1: Block level description of the WUSB host controller.
