Attachment Comtech ltr

Comtech ltr

LETTER submitted by Comtech Mobile Datacom Corporation (CMDC)

Comtech ltr

2008-10-03

This document pretains to SES-MFS-20070530-00731 for Modification w/ Foreign Satellite (earth station) on a Satellite Earth Station filing.

IBFS_SESMFS2007053000731_669477

KELLEY DRYE & WARREN uce a uzen useiuiry rantuensiue WASHINGTON HARBOUR, SUITE 400 new vyorak. wy 3050 K STREET, NW racsimice ehicaeo, it WASHINGTON, D.C. 20007—5108 crorg sazcsasd stamroro, or www kelieydrye.cam ransirrany. No (202) s42—8400 mrusseis. seroium DIRECT LINE: (202) se2—0573 arsuuate oreices Mumear mork EMAIL: jqriffin@kelteydrye.com October 3, 2008 EDACCEPFEp F BY MESSENCER a OC7 _ 3 2008 era;cOm . Marlene H. Dortch orfi,;em‘;""’afiwmcg h Secretary ° mese‘?feaar’;mlss"’" Federal Communications Commission 445—12" Street SW Washington, DC 20036 Re: Comtech Mobile Datacom Corporation Modification of Blanket License to Operate Data Terminals in the L—Band File No. SES—AMD—20070907—01251, E990143 Dear Ms. Dortch: Comtech Mobile Datacom Corporation ("CMDC"), by its attorney, submits this letter with the following clarifications and additional information regarding CMDC‘s request for a waiver of footnotes US308 and US315 to the U.S. Table of Frequency Allocations and Section 25.136(d) of the Commission‘s Rules (Exhibit B to FCC Form 312, Schedule B, of CMDC‘s modification application ("Exhibit B")). Since filing its revised and updated Exhibit B on June 3, 2008, CMDC has tested and further analyzed its MET‘s vis—a—vis their compliance with the real time access and priority preemption requirements in footnotes US308 and: US315. It is CMDC‘s understanding that NTIA will consider a terminal to satisfy the realtime access and priority preemption requirements in footnotes US308 and US315 if the terminal is capable of, among other things, ceasing transmissions and inhibiting further transmissions within one second. CMDC interprets this benchmark as meaning that each MES for all ofits operating modes must, within one second of receiving a shutdown command, stop all ongoing RF transmissions and prevent any new RF transmissions. Based on CMDC‘s testing and further analysis, CMDC refines and supplements its waiver request as follows. DCOL/GRIFI351543.3

KELLEY DRYE & WARREN ucr October 3, 2008 Page Two At present, CMDC has approximately 70,000 activated terminals in service worldwide, of which approximately 6,500 operate in the U.S. during any given month. Virtually all of CMDC‘s METS that operate in the U.S. are CMDC model MT2011 or MT2012. Based on CMDC‘s recent tests and analysis, CMDC has determined that the MT2011 and MT2012 terminals do »mor operate with the two—second timeout parameter described in Exhibit B.‘ This means that the MT2011 and MT2012 MET‘s that operate in CONUS will satisfythe real time access and priority preemption requirements in footnotes US308 and US315, as the total time required for each of these MET‘s to stop all ongoing transmission and prevent any new transmission is no more than 400 milliseconds (maximum message length and data rate). Only the MT2011 and MT2012 METs that operate in Alaska or Hawaii require more than one (1) second to shut down and disable their transmitters. The MT2011 and MT2012 METs that operate in Alaska or Hawaii, because they operate at a slower(4) data rate, require 1.6 seconds (the transmission duration of a full length message at !4 data rate). Both commercial and government customers (including the U.S. Army Logistic Command‘s Movement Tracking System ("MTS")) use MT2011 and MT2012 METs. These MET‘s are used throughout the U.S. CMDC METs with model number MTM202 also operate in the U.S. The MTM202 METs have the two (2) second timeout parameter discussed in Exhibit B. As such, these METs require a maximum of 2.4 seconds in CONUS and 3.6 seconds in Alaska and Hawaii to stop all ongoing transmissions and prevent any new transmissions. However, there are only 900 of these METs in existence, and on average, only 10 in operation in the U.S. (mainly in CONUS) on any given day. Importantly, the MTM202 is at end oflife; while CMDC is selling units in stock, it is not building any new units. The U.S. Army‘s Force XXI Battle Command, Brigade and Below ("FBCB2") command and control system, also known as Blue Force Tracking ("BFT"), operates the MTM202 MET‘sin the U.S. and worldwide. CMDC is currently developing a new model MET, the MTM203. At present, approximately 200 MTM203 METs have been built, but no more than 30 units are in the field in the U.S. Most of the existing MTM203 METs have been given to software developers for experimental purposes. The MTM203 shares the same operating characteristics as the MTM202 and thus currently has the two (2) second timeout parameter discussed in Exhibit B. However, CMDC is in the process of changing this parameterto largely eliminate the two—second timeout. Once this modification is made, the MTM203 MET‘s will require no more than 600 milliseconds {maximum message length and data rate) when operating in CONUS, and 1.8 seconds when operating in Alaska or Hawaii, to stop all ongoing transmissions and prevent any new transmissions. Thus, once modified, the MTM203 METs operating in CONUS will satisfy the real time access and priority preemption requirements in footnotes US308 and US315 but the I As CMDC explained in Exhibit B, the two—second timeout parameter means that when a MES detects a loss of forward link (the link from the hub station to the MES}, the MES will continue to monitor the forward link for an additional two seconds to confirm that the carrier is down before disabling the transmitter. DCOL/GRIFI/331545.3

KELLEY DRYE & WARREN ucr October 3, 2008 Page Three METs operating in Alaska and Hawaii will not. CMDC expects to complete this modification by the end of 2008. CMDC has made no commitments to government or commercial customers with respect to the timeout parameter on the MTM203 MET‘s and has no reason to believe that any existing or potential customer will be concerned about this change. Thus, not every CMDC MET requires a waiverof the real time access and priority preemption requirements in footnotes US308 and US315. The only MET‘sthat require a waiver are as follows: e The MT2011 and MT2012 MET‘s that operate in Alaska or Hawaii. These METs employ the antennas denoted as A5, A6, and A7 in CMDC‘s modification application. e The MTM202 METs operating in the U.S. The AS antenna is used with this model MET. e The MTM203 MET‘sthat operate in Alaska or Hawaii. The MTM203 METs use the A5 and A6 antennas. As noted previously, there are very few MTM202 METs operating in the U.S. —— only about 10 on any given day. Furthermore, there are very few MET‘s of any type operating in Alaska or Hawaii. As CMDC noted in Exhibit B, CMDC has analyzed data from its operations in the U.S. over an 8—month period, and has determined that only an average of 2900 packets per month had a transmission duration of 1 second or longer (only Alaska or Hawaii transmissions have a maximum message duration longer than 1 second). For all of CMDC‘s U.S. traffic, the 1— second transmission duration is exceeded on average only 94 times per day, or 0.1% of the day. If you have any questions regarding this matter, please contact the undersigned counsel. Please date—stamp the duplicate copy of this letter and returnit to the bearer. DCOVGRIRI/3S1545.3

KELLEY DRYE & WARREN ucr October 3, 2008 Page Four Sincerely, ComTECcH MosILE DaATACOM CORPORATION By: Joan M. Griffit Its Attorney ce: Scott Kotler Karl Kensinger Chris Hofer (NTIA) DCONV/GRIRI3S1545.3


Document Created: 2008-10-09 11:43:14
Document Modified: 2008-10-09 11:43:14
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