Response to 5 and 7

0126-EX-PL-2005 Text Documents

NextNet Wireless

2005-04-22ELS_70333

 In support of NextNet Wireless’s application for an Experimental License in the
                               2.3-2.4 GHz band



Proposed program of Research and Experimentation

NextNet wireless has undertaken the design of a new radio product, operating in the 2.3-2.4 GHz
band for the delivery of Broadband Wireless services. These products are derivatives of currently
deployed products in the American market:
                     • PHX-MMDS-BASE2           Base Station
                     • PHX-MMDS-CPE5            Residential Subscriber Unit
                     • PHX-MMDS-CPE6            Outdoor Subscriber Unit
                     • PHX-MSU2510A             Mobile Subscriber Unit

The 2.3-2.4 GHz products are intended to be sold and used only in foreign countries.

The development program comprises the design and testing of new transmitter and receiver
circuitry, based on those of the existing Broadband Radio Service (“BRS” formerly MDS) and
Educational Broadband Radio Service (“EBS” formerly ITFS) products, verification of the design
against regulatory requirements of a number of Pacific Rim countries, and extensive ongoing
testing of the system level performance of the product in laboratory and field conditions.

System Operation

NextNet Expedience™ is an end-to-end, high-speed wireless network access system designed in
a number of licensed bands from 2.3-3.6 GHz. It is a local loop wireless alternative offering
business and residential users high speed access to network communication systems, such as
private networks and the Internet. The system consists of two major components:

            1) a base station component connecting to a service provider’s backbone network
               which may ultimately provides access to the Internet, and
            2) a subscriber unit (CPE) installed and operated at each end user’s computer.

The base station may be deployed in a cellularized and sectorized fashion and is designed to
provide high speed throughput for dense user capacities. It is targeted to be best utilized and
deployed in high density suburban or urban areas. The base station coverage area (sector) is
approximately a 1 to 3 mile radius from the transmitting tower in an urban deployment, 20 miles
maximum in rural applications where the terrain permits. These sectors may overlap when an
additional base stations are deployed thus allowing a given user in an area to potentially
communicate to one of multiple base stations depending upon the signal quality. Adding a base
station to a cell increases the user density and maintains the quality of service intended for a
particular subscriber.

The subscriber unit or customer premises equipment (CPE) is a transceiver, modem and
directional antenna integrated into a single enclosure. The CPE is a low cost, customer-installable
device. This is intended to be mass marketed and sold as a consumer device, much in the same
way as dial-up modems or other commercial off the shelf components are sold.

The NextNet air link functions as an IP Ethernet bridge. NextNet CPE, if able to receive signals
from more than one base station, are able to select the base station providing the best quality
signal.

The modulation used is orthogonal frequency division multiplexing (OFDM). The OFDM shall
consist of 1024 sub-carriers with only 811 sub-carriers transmitted. Each sub-carrier is


modulated using 4QAM, 16 QAM, or 64QAM on each of the information sub-carriers in each
OFDM modulation symbol. The order of QAM modulation is automatically and dynamically
selected by the system for each link between base station and CPE, based on the measured
channel quality.

Time division duplex and cellular deployment support considerable flexibility in adjusting downlink
vs. uplink airtime to actual two-way traffic flow. The downstream/upstream ratio is selectable by
the system operator, with values in the range of approximately 1:1 to 5:1. The resultant transmit
duty cycle of the base station ranges from 42.9% to 74.2%; the resultant transmit duty cycle of a
CPE during a continuous upload at maximum throughput ranges from 3.3% to 14.3%.

The system channel bandwidth is adjustable over the range of 3-7 MHz.

Maximum output power of both the base station and CPE is 2.0W. In normal operation, the base
station operates at a constant 2W output level during its transmit cycle. The CPE is automatically
adjusted in the range of 0.2 mW to 2W, dependant upon its distance from the base station, and
the channel conditions, to produce a minimum acceptable receive signal level at the base station.

The EIRP of the base station is dependant on the antenna used, which is engineered according
to the cellularization plan employed in a particular deployment. The CPE has a built-in antenna,
whose gain varies with the band used. In this band, the CPE antenna gain is approximately 13
dBi.

Specific Objectives of the Experimentation

The product is expected to evolve significantly as new markets are developed, and there is need
for ongoing validation of design changes and new system applications. Validation of the initial
product, and of subsequent design changes, requires extensive testing of the radio performance,
including features such as automatic adaptive modulation operation, transmitter power control
operation, operation of TDD functions, such as ranging and turn-around time, and sector-sector
handoff operation for nomadic or mobile applications. This can only be accomplished using a
multi-sectored on-the-air test environment, as provided with the use of this experimental license.

Contribution to the development, expansion, or utilization of the Radio Art

NextNet Wireless’ Expedience product is the first practical Non-Line-of-Sight broadband wireless
access product, and in its 2.5-2.7 GHz version is widely deployed in the United States, as well as
several other countries. NextNet’s OFDM airlink is very similar to that of the proposed IEEE
802.16e standard, and delivers the range of features planned for this evolving standard. NextNet
is currently partnering with the major developer of chipsets for this evolving standard, and is
providing guidance for the optimization of this new standard, based on ongoing experimentation
with the Expedience product. This experimental license will assist NextNet to expand this new
technology into a new band, as used extensively in Pacific Rim countries, bringing the benefits of
effective NLOS technology to new world markets.



Document Created: 2005-04-22 12:31:56
Document Modified: 2005-04-22 12:31:56

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