Mark-IV Two Way Radio

Mark-IV Digital Narrowband Signal Booster

The Mark-IV Narrowband Class-A BDA is "America's Street Legal BDA". The FCC in 1996 issued rule 90.219 allowing for Class-A BDA's to be used for in-building coverage extensions for Public Safety and Private Land Mobile services. The Mark-IV Narrowband Class-A BDA meets or exceeds all of the FCC part 90.219 requirements for in-building rebroadcast using an over-the-air interface.

FCC 90.219 rule has never allowed for Class-B Broadband boosters to be used for over-the-air interface (except for rural sites). The Broadband Class-B BDA's use in urban areas is restricted exclusively within an enclosed environment e.g. a Tunnel or a large Building, as the FCC 90.219(d) rule states "Class-B broadband signal boosters are permitted to be used only in confined spaces or indoor areas such as buildings, tunnels, underground areas, etc., or in remote areas, where there is little or no risk of interference to other users."

According to the FCC letter of June 2005: "In allowing Class B boosters, the Commission noted the increased interference potential inherent in such devices. To minimize interference, the Commission limited Class B signal boosters to areas that are confined or enclosed (confined areas) such as tunnels, underground parking garages and within buildings i.e., areas where there is little or no risk of interference to others. See 47 C.F.R. 90.219(d). Therefore, Class B boosters cannot be used for a communications link that emits radio frequency energy outside a confined area i.e. designed to be a communications link between a confined area and a base station as described in the attachment to your letter. Allowing this type of operation would increase the interference potentional to other users in the area, specifically what the Commission was trying to avoid when it restricted Class B Bosters to confined areas."

Many vendors had existing Class-B BDA products that were sold to Public Safety Agencies, however FCC 90.219 clearly specifies that any BDA used for over the air interface must be a Class-A. Therefore any Public Safety Agencies currently using or recommending to building owners the use of Broadband Class-B BDA's may be in direct violation of FCC 90.219. See the June, 2005 FCC Letter.

The Mark-IV Digital filters can be configured as Class-A BDA Narrowband (Channelized) Signal Booster to meet the demands of current and future digital radio systems and the FCC Rule 90.219(d) requiring Class-A Narrowband Signal Boosters to transmit only the user licensed frequencies on the uplink over-the-air path to the donor sites or base-repeaters.

The Mark-IV Digital’s patent pending design is for multi-carrier two-way rebroadcast, where significantly high dynamic range is required on a channel-per-channel basis, while delivering lower & flatter group delay. Effective coverage and dynamic range to simultaneously handling weak and strong incoming signals are enhanced by Automatic Gain Control on a per-filter window basis.

The filters’ bandwidths & selectivity are software-defined and the system personality could be selected by the user in order to achieve very narrow filters windows, such as 100 KHz BW for less than 10 uSec delay per filter, or 12.5 KHz BW with 60 dB rejection at 50 KHz offset for less than 30 uSec delay.

For compliance with the FCC Rule 90.219(d) to transmit uplink over-the-air back to the donor sites, the uplink path filters selectivity can be set as a TRUE Class-A Signal Booster per FCC 90.7 definition, with less than 110 uSec delay. In addition, the downlink path filters can be broader for reduced delays to accommodate the digital modulation signals timing constraints in the overlap coverage areas.

The Mark-IV Digital programmable filters deliver Flat Group Delay (Linear Phase response) within their passband, a must for today and tomorrow’s digital modulation formats.

The Mark-IV Digital filters stage could also be used to retrofit existing Class-B Broadband Bi-directional Amplifiers (BDAs), converting them into Class A Narrowband (Channelized) Boosters compliant with the FCC Part 90.219(d) requirements to transmit outdoors.