Wireless Communications Enhanced by Newly Patented Propagation Technology

(Fairfax, Virginia, June 7, 2007) Saraband Wireless Inc., (Saraband) established to advance the capabilities of broadband wireless devices and systems, announced today the company has received a U.S. patent on a ground-breaking propagation approach that significantly enhances the performance of broadband wireless communications.

The Saraband technical solution dramatically improves radio frequency (RF) data transmissions between communicating devices by continuously measuring and adjusting for channel state propagation path conditions. Conducted with an inventive self-correcting feedback loop that synchronizes crystal oscillators in distant devices, the Saraband solution considerably improves the throughput and reach of non-line-of-sight (NLOS) broadband communications.

Saraband's advanced technical approach to signal propagation overcomes many of the performance and penetration problems of existing wireless Internet Protocol (IP) packet transmitting systems, while greatly extending the effective range and allowing for considerable reduction in the infrastructure costs of broadband wireless communications.

As a supplemental 'propagation analyst- on a chip application, the Saraband solution can be used to enhance a wide variety of WiFi, WiMax and other wireless broadband platforms. Tested and verified under a National Science Foundation grant, wireless NLOS broadband signals were successfully transmitted utilizing this system at a range that exceeded 13 miles. Using this system, which has not been productized, NLOS wireless broadband communications between two points will be significantly and cost-effectively extended.

Developed by wireless and satellite industry pioneers, Drs. Donald Arnstein, Ph.D. and Paul Ebert, Ph.D., (who first collaborated as MIT Graduate students in the 1960's), the Saraband communications solution expands upon the concept and capabilities of traditional vector network analysis devices, which conventionally measure the conveyance and any modulation distortions of electromagnetic signals transmitted from one source point to another. The Saraband Vector network analyzer appliqué (VNAA) applies a unique and now patented feedback system that aligns, with atomic like accuracy, the timing of separate low cost crystal oscillators that can be positioned miles apart and used to accurately determine and communicate the conditions of a propagation path in real time.

In describing the Saraband technology, Donald Arnstein, the President of Saraband remarked; 'We took the traditional vector analysis concept, which is usually contained in a single apparatus set on a workbench, and split this communications channel measuring device into two halves so the test signal injector and test signal receiver can be separated by many miles and made an integral part of the wireless transmitter and receiver communications link. This provides an extremely accurate situational awareness of channel state conditions, and surprisingly this is not available in wireless equipment today, not even with WiMax."

The over-the-air vector link, which had never been accomplished before, provides highly accurate channel state measurements, rather than the conventional estimations that prevail in current wireless systems.

Through the use of continuous channel signal sweeps generated from the transmission point and then back from the synchronized signal receiver, immediate and continual measurements of amplitude versus frequency and phase shift versus frequency characteristics of the propagation path are made. These dynamic two way measurements are combined with an adaptive processing circuit, which uses these measurements to correct for any channel interference, which is communicated ahead of IP data packet transmittals.

Through the use of the Saraband system, channel state conditions are continuously conveyed back to the transmittal circuit via a control channel, which allows for subsequent and instantaneous changes in the appropriate communication parameters, including the transmission data rate, selection of modulation and forward error correcting coding, and selection of transmission frequency band. The channel state measurements are also concurrently conveyed to an adaptivity function at the receiving end to select and adjust demodulator variables such as gain control, and equalization of amplitude and phase, versus frequency. According to Saraband ‘s developers, this is more efficient and effective than the current leading WiFi and WiMax 802.11 and 802.16 methods of sending data preambles and IP packet pilot tones to gauge channel characteristics.

Current wireless broadband systems use several different methods in helping to transmit radio frequency (RF) signals through a channel path; among them preambles, training sequences, and the most common approach, pilot tones embedded in the IP data packets. The Saraband solution achieves connections more accurately and efficiently than any of these methods, and when implemented will result in greater utilization of the frequency spectrum and far less infrastructure related costs.

By creating highly accurate situational awareness of a channel state's propagation conditions, Saraband's VNAA is a value add solution that works in combination with any current physical layer modulation techniques. Whether a system is utilizing WiFi or WiMax, the Saraband solution will permit more rapid and efficient allocation of bandwidth transmitting resources.

About Saraband
Saraband was established in 2001 to further the capabilities of broadband wireless devices and systems through advanced propagation technologies. Among telecommunications experts engaged in the technologies of RF signal propagation, the Saraband Vector network analyzer appliqué is seen as a historic engineering breakthrough that will contribute greatly to the advancement of Wireless Non-line-of-sight broadband communications.