| Taming
the Spectrum
In this issue: CASE CORNER NYC Telecom Recovery Efforts Following the Terrorist Attacks MARKET TRENDS Municipalities Seeking Help REGULATORY RAP MAS Spectrum Auction: New Interference and Coordination Issues CONTACT US  Subscribe Unsubscribe Click here for text only version |
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Your e-newsletter with Innovative Solutions for the Wireless World www.comsearch.com |
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| November 2001 Vol 1 Issue 1 ©Comsearch 2001 | ||||
 Case
CornerNYC Telecom Recovery Efforts Following the Terrorist Attacks by Tim Fitzgerald and Les Polisky Long recognized in the telecommunications industry as experts in microwave and mobile communications, we were honored to assist in the restoration of the telecommunication systems that were decimated by the attacks in Manhattan. The challenges ahead were unknown, but the objective was clear: Quickly bring the cellular and PCS systems back into operation to assist in the search, rescue and recovery efforts at Ground Zero. The key to success would rely on fast and efficient deployment, project management, planning, and engineering. To bring the cellular and PCS systems back into operation, Cell on Wheels (COW's) were set up in lower Manhattan. The COW's had to be interconnected to the landlines and telephone switches in Manhattan, Brooklyn, and New Jersey via Microwave links. The decision to use unlicensed short-range spread spectrum radios in the 2.4 and 5.8 GHz frequency bands for the microwave links would serve well as an efficient temporary measure. The short range of these unlicensed systems required multiple microwave hops for paths where a single hop at 4- or 6-GHz would have been sufficient. Perhaps not an ideal solution under normal circumstances; however, the use of unlicensed radios allowed for quick installation of the microwave links without the delay associated with obtaining Federal Communication Commission (FCC) licenses. The process of installing licensed radios at 4- and 6-GHz will take place after all of the emergency restoration work is completed and the area is brought back into a more stable physical condition. Although coordination is usually not necessary for unlicensed radios, it was recognized that if all of the major cellular and PCS carriers in the New York area were to use unlicensed radios there could be serious interference problems. Because these systems would be in use for many months, frequency coordination was essential to identify and prevent interference conditions in the unlicensed spectrum. In addition to the installation of these temporary networks in Manhattan and the surrounding areas, Comsearch was selected to be the coordination agent for all carriers in New York. Under normal circumstances this job would be a tough undertaking, but given the chaotic conditions in lower Manhattan, the job was doubly difficult. Upon initial evaluation and organization, it became clear that this was no ordinary job, and that the grave conditions would present many roadblocks, both literally and figuratively. Recognizing the critical importance of the job, the crew had a strong desire to get the networks running as quickly and efficiently as possible. Patience would prove to be essential because nothing moved quickly in the aftermath of September 11th. The obstacles encountered throughout the project included gaining access to restricted areas, lack of line-of-site conditions at some of the proposed links where COW's were located, absence of electricity in much of lower Manhattan, crazy maze-like traffic patterns, and police check points at nearly every block. Frustration became apparent as the job progressed slowly and the workdays stretched late into the evenings, but when put into perspective with the other activities at Ground Zero these frustrations were admittedly minor. After given access to the Ground Zero area, our crew stood in awe at the enormity of the devastation. To fully grasp the magnitude of the destruction one must see it first hand - no television production could ever quite capture the scenes and moods of Ground Zero in their entirety. Smoke and flames billowing from the giant piles of rubble, heaps of burned and crushed emergency vehicles, shattered windows and crumbling facades of neighboring buildings, massive steel beams twisted and contorted by the destruction, and the solemn and exhausted faces of the rescue crews were the unforgettable images of Ground Zero. It was these sights that quelled some of the frustrations that were encountered by our team, realizing that there were greater issues than the annoyance of yet another checkpoint. Through the cooperation of the various carriers, the city, and the property owners and managers, Comsearch completed the installations and restored service to Ground Zero. Installation shifts typically lasted 16 to 18 hours. With so much time spent waiting in traffic, gaining access to restricted areas, and handling logistics such as electrical power and equipment deliveries, the crew relished time spent on the actual installations. Unpredicted challenges were faced with sheer determination. One microwave site was located on a building without electricity. Overcoming the absence of electricity is one thing, but not having a working elevator in a twenty-story building was one obstacle that nobody wanted to face. Dedicated to the job at hand, the crew trudged tirelessly up to the roof with all the necessary equipment and completed the installation. Although the work was long and slow, it was also completed in a manner that was thorough and of high quality. With cellular and PCS coverage restored to Ground Zero and the surrounding areas, our team of engineers felt a proud sense of accomplishment. One Comsearch team member was approached by a city police officer who thanked him for his efforts to restore communications in Lower Manhattan, noting how important it was for emergency personnel to have reliable communications in the area. With that simple gesture, the police officer clearly made all the long hours and tireless efforts of the Comsearch team well worth while.  |
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With a marked rise
in requests for telecom tower sitings, local governments are looking
to improve their processes for granting zoning and site-plan approval.
In addition, they're realizing that their Public Safety communications
systems may suffer from inadequate coverage or frequencies during event-specific
or emergency communications. They're looking for help. Changes in commercial telecommunications have caused a great demand for additional antenna mounting facilities. The increased demand for these facilities poses a number of important land use issues for local governments including collocation of antennas, ensuring appropriate siting and design, and mitigating impacts of telecommunications facilities. Municipalities also want to create an attractive economic development environment. Recognizing that modern, effective, and efficient telecommunications is an essential part of meeting the needs of its citizens to have high quality services, local governments are looking to develop telecom master plans in the same way they develop such master plans for other infrastructure needs. Municipalities are finding it necessary to develop Wireless Communications Infrastructure plans that address not only commercial use of spectrum, but local and surrounding Public Safety use as well. Local governments have been hit with the reality that their telecommunications systems may not be able to handle large-scale disasters such as the September 11 terrorist attacks. The emergency response to these attacks, both at the World Trade Centers and at the Pentagon, drew in rescue forces from several jurisdictions and disciplines. The profusion of public safety land mobile and trunked radios caused several instances of interference and poor coverage. Newspapers reported that at the Pentagon, rescue workers literally had to shout instructions to each other rather than use their radios due to frequency congestion and coverage problems. The cross-jurisdictional nature of these issues, and the sometimes unique expertise needed to resolve them is sending local governments in search of help. Some of what municipalities are seeking includes: RF Measurements and Site Surveys:Although there is no obvious panacea, development of comprehensive Wireless Communications Infrastructure Plans will help local governments deal with these myriad problems at once. Indeed, many of these issues can be better addressed through a concomitant coordination of efforts as described in these plans. Given the increased attention to Public Safety and municipal telecommunications, these plans couldn't be more timely. |
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Regulatory Rap MAS Spectrum Auction: New Interference and Coordination Issues by Chris Hardy The FCC's upcoming auction of Multiple Address System (MAS) licenses in the 928/959 and 932/941 MHz bands is a significant departure from traditional site based licensing and brings with it a myriad of new engineering, coordination, and interference issues to consider.
FCC Auction 42
The Commission created the following new operational rules for MAS EA licensees. While these rules were designed to afford maximum flexibility to the license winners, they could increase the potential for interference problems with both incumbents and neighboring EA licensees. 101.1333(a): "All EA licensees are required to coordinate their frequency usage with co-channel adjacent area licensees and all other affected parties." Coordination of frequency usage between potentially affected parties is a very efficient and effective means to avoid interference problems before they occur. This process of notification and response has been used successfully with site based licenses, due in part to the requirement that an applicant must file a showing with the Commission that coordination has been successfully completed. This showing identifies the licensees included in the coordination notification and certifies that no outstanding interference problems exist. Access to this information through the FCC's licensing database provides other operators in the band with a means to verify that they are being correctly notified and to take action if necessary. Unlike site based systems, EA licensees are not required to file a certification of coordination completion so this important "checks and balances" is no longer applicable. While the new EA licensees are required to coordinate "with all other affected parties", it is unclear how these affected parties will be determined. This unilateral determination of who should receive a coordination and when could lead to a chaotic interference environment. For new EA licensees, it will be imperative to know the name and location of the incumbents and other EA licensees. The map on the front page indicates how the current 90-mile radius of protection for an MAS Master Site can overlap multiple EAs. This situation will require incumbents and EA licensees to deal with potentially numerous entities during the coordination process. Many of the twenty-nine license blocks up for auction are in use by existing site based license holders. If you are an incumbent, the protection from interference afforded to you in the past will no longer be applicable. Under the new rules a neighboring EA licensed system may produce a co-channel interfering field strength of up to 40 dBµ at 25 miles from an incumbent site-licensed MAS master station. Under the previous rules, two co-channel site-licensed MAS master stations could be located no closer than 90 miles without a short-spacing agreement. Simple signal strength limitations along boundaries may be insufficient to protect all incumbent systems and other adjacent EA operations. Comparing the traditional 90 mile distance criteria and the new field strength requirement, our analysis indicates that EA licensed systems will generally be allowed to produce greater levels of interference to incumbent site-licensed systems than the levels of interference these systems receive under site-by-site licensing. Since traditional MAS engineering was accomplished based upon a simple distance criteria, the need for a standardized interference algorithm or propagation model was unnecessary. Now that the more complicated field strength calculations will be required, it will be necessary for the industry to determine the appropriate interference methodology to employ. Without consensus on the correct approach, incumbent licensees and neighboring EA licensees will be at the mercy of each individual EA operator to run the appropriate analyses, correctly interpret the results, and determine the level of potential interference into his and other's systems.
The
introduction of area wide licenses in the MAS bands poses new interference
and coordination issues for both incumbents and the auction winners.
For coordination and analysis to work effectively in this new environment,
both incumbents and the new EA licensees need to be keenly aware of
the issues and must work together to develop a consensus approach.
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