Alereon's innovative wireless chipsets utilizes revolutionary ultra wideband technology. Ultra wideband radio signals are defined as having a bandwidth greater than 20% of the center frequency, providing much wider bandwidths than used in conventional narrowband transceivers. This is advantageous in terms of channel capacity. The theoretical capacity of any communication channel increases logarithmically with the signal power, but linearly with bandwidth. In practical terms, a 10x increase in power only allows a 2x data rate increase in a conventional system, but a 10x increase in a UWB system. In addition, UWB signals can be transmitted at very low power levels allowing them to coexist with other signals with no effective interference.
Multi-band Orthogonal Frequency Division Multiplex (OFDM) uses similar technology to that employed in 802.11g, 802.11a, and 802.16 to achieve high spectral efficiency and excellent multipath immunity --- but adapted to the unique requirements of ultrawideband channels to deliver performance far beyond what is possible with these narrowband standards. In MB-OFDM, a wide (>500MHz) OFDM signal is interleaved over time and frequency across 1.5GHz to create high speeds, good range, excellent multipath immunity, and minimal interference. Alereon was one of the early developers of this multi-band approach, and continues to be at the forefront of its development.
Alereon's ultra wideband chipset implements multi-band OFDM which allows for the use of lower-rate analog-to-digital and digital-to-analog converters, and simplifies other analog components, reducing overall design complexity, power consumption and cost, and ultimately speeding time-to-market. The benefits of the multi-band OFDM approach in Alereon's first chipset include:
- digital-centric, CMOS-friendly design
- higher integration
- lower power consumption
- cost tracking of Moore's Law
- precise sculpting for coexistence
- ~100% multipath energy capture
Wireless USB technology employs Ultrawideband (UWB) method, a high-speed communication technology for short-distance communication via a wide band. Aiming to become the wireless version of USB 2.0, UWB offers the following merits exploiting the features of USB 2.0.
Wireless transfer rate of up to 480 Mbps, the same as USB 2.0
A feature of wireless USB is that the data transfer speed across a distance of approximately 3 meters, a typical range for the connection of personal computers and peripherals, can theoretically reach 480 Mbps, a rate equivalent to that of the existing USB 2.0 standard. This makes the installation of equipment requiring high-speed transfer of large amounts of data, such as printers and external storage, very easy, and eliminates the need to carry around cables for transferring data from portable devices such as portable HDD players and digital cameras to a personal computer.
Same ease of use and convenience as existing USB devices
The wireless USB standard has a lot in common with the existing USB standards, and existing systems can be adapted to wireless USB by fitting them with a wireless USB module either internally or externally. It is thus possible to continue using existing drivers in personal computers, etc.
Power saving and low-cost development
The use of the MB-OFDM (Multi-Band OFDM) method allows the realization of lower power consumption transmission/reception circuits in addition to high-speed wireless communication. Moreover, in cases when there are several personal computers and peripherals, wireless USB communication achieves a reduction in circuit scope by limiting the network connection mode to one-to-many, by defining beforehand a master/slave relationship among devices such as "host (personal computer, gaming equipment, etc.)" and "devices (peripheral devices)", unlike a wireless system that assumes many-to-many communication. Moreover, since CMOS technology can be used in the RF processing block, it is possible to continue using existing production lines, allowing for cost saving as well as easy support of future integration.
Security
Host devices that support wireless USB can communicate with each other without special settings. The trade-off is that when security settings are not performed, anyone within the transmission range can receive the transmitted data, meaning that data may be stolen or rewritten without the user being aware of this, and thus predetermined countermeasures are required. Wireless USB uses a system based on special procedures between the host and devices in order to ensure a level of security comparable with wired communication.