Attachment Exhibit D (Q. 35)

This document pretains to SES-MOD-20130206-00159 for Modification on a Satellite Earth Station filing.

IBFS_SESMOD2013020600159_984923

                                                    Comtech Mobile Datacom Corporation
                                                                          FCC Form 312
                                                                        Exhibit D, Page 1
                              ROUS (E090027) Modification Application – February 6, 2013



                                      Request for Waiver

        Comtech Mobile Datacom Corporation (“CMDC”) requests a two-year waiver of
footnotes US308 and US315 to the U.S. Table of Frequency Allocations and Section 25.136(d)
of the Commission’s Rules with respect to the operation of its MTM202 half-duplex terminals
outside of the continental U.S. (“CONUS”). These provisions are intended to protect maritime
mobile-satellite service distress and safety communications in the lower L-band and aeronautical
mobile-satellite service distress and safety communications in the upper L-band from
interference.

        As discussed below, CMDC’s MTM202 terminals comply with the requirements listed in
Section 25.136(d) of the Commission’s Rules for the protection of maritime mobile-satellite
service distress and safety communications in the lower L-band, and the equivalent requirements
for the protection of aeronautical mobile-satellite service distress and safety communications in
the upper L-band.1 However, these terminals do not comply with the National
Telecommunications and Information Administration’s (“NTIA’s”) interpretation of footnotes
US308 and US315. NTIA determined in the NTIA 2009 Letter that if a terminal meets certain
minimum requirements and is capable of ceasing transmissions and inhibiting further
transmissions within three (3) seconds, that terminal would be considered to meet the real time
access and priority preemption requirements in footnotes US308 and US315.2 CMDC’s
MTM202 terminals are unable to cease transmissions within three (3) seconds when operated in
certain locations outside of CONUS, most notably Alaska and Hawaii.

       CMDC demonstrates below that there is good cause for granting a waiver of footnotes
US308 and US315 as well as Section 25.136(d). There are only about 900 MTM202 METs in
existence today, and no additional MTM202s are being built. Worst case, the MTM202 requires
only 3.6 seconds to shut down when operated outside of CONUS. These terminals currently
operate outside of CONUS on the MSAT satellites, SkyTerra 1, and ISAT pursuant to a waiver.3
Grant of this waiver request is appropriate and consistent with prior precedent, including the


1
       See Amendment of Part 87 of the Commission’s Rules to Establish Technical Standards
       and Licensing Procedures for Aircraft Earth Stations, 8 FCC Rcd 3156, ¶ 5, n. 22 (1993),
       citing Letter from Richard D. Parlow, Associate Administrator, Office of Spectrum
       Management, NTIA, and Gerald Markey, Manager, Spectrum Engineering Division,
       FAA to Cheryl Tritt, Chief, Common Carrier Bureau, FCC, dated January 14, 1993
       (“NTIA/FAA Letter”).
2
       See Letter of Karl B. Nebbia, Associate Administrator, Office of Spectrum Management,
       U.S. Department of Commerce, NTIA, to Mr. Julius Knapp, Chief, Office of Engineering
       and Technology, FCC, May 13, 2009 (“NTIA 2009 Letter”).
3
       See IB File Nos. SES-LIC-20090211-00164, SES-MOD-20090923-01223, and SES-
       MOD-20110131-00094.


                                                     Comtech Mobile Datacom Corporation
                                                                           FCC Form 312
                                                                         Exhibit D, Page 2
                               ROUS (E090027) Modification Application – February 6, 2013

requirements of the NTIA 2009 Letter. Accordingly, CMDC respectfully requests that the
Commission grant this waiver request.


Description of CMDC System

        CMDC provides wireless packet data services from mobile terminals throughout the
United States and overseas. CMDC terminals typically are placed on land vehicles or at remote,
fixed site locations. Either data collection devices or keyboard/displays, or both, may be
attached to the terminals depending on the customers’ needs in that location or at that time.

        The terminals transmit and receive data packets via L-band dedicated channels. CMDC’s
system is capable of using L-band channels from any carrier providing such services in the U.S.
The packets can be routed over any of several terrestrial data networks, or to other mobile
transceivers in the CMDC network. Use of the satellite relay is as a “bent pipe,” meaning that
only bandwidth and power are purchased from the satellite relay operator. Network management
is provided by CMDC-owned and operated gateway sites.

        The wireless packet data network is bi-directional, and transmission can be asynchronous
in both directions. When powered on, terminals are either listening for packets addressed to
them - individually or in groups - from a gateway station, or are transmitting packets in short
bursts to a gateway station. Other modes of operation are possible, including periodic reporting
from a terminal to a customer’s operation center, via a gateway, and polled queries to the
terminals by either the gateway or operation center.

        The mobile transceivers transmit and receive direct sequence spread spectrum bursts. In
CONUS, the typical burst duration is less than 100 milliseconds, while the maximum burst
duration is about 400 milliseconds. In Alaska, Hawaii, and U.S. possessions and territories
within the footprint of the satellite, a reduced data rate service is employed that results in a
maximum burst duration of 1.6 seconds. Bursts from any individual transceiver are usually a
minimum of several minutes apart. This means that the maximum interval during which a
transceiver will not be listening to the outbound channel is less than 0.4 seconds (1.6 seconds in
Alaska, Hawaii, and U.S. possessions and territories within the footprint of the satellite) and
represents only a small fraction of one percent of its operating time.

        In normal operation, a packet of information sent by a mobile terminal will be received
by the CMDC gateway station, then routed to the designated recipient via the Internet, dedicated
links, or the CMDC network outbound channel. There are no constraints on the routing of
packets, though mobile-to-mobile, mobile-to-operation center, and operation center-to-mobile
represent the majority of the traffic.

         The mobile terminals can be tuned to transmit and receive across the entire L-band. This
is to facilitate access to available bandwidth on the satellite relays, since the satellites operate
many beams, and any one frequency may not be available across all beams. The outbound
beams broadcast their identity in the form of network management packets from which the


                                                    Comtech Mobile Datacom Corporation
                                                                          FCC Form 312
                                                                        Exhibit D, Page 3
                              ROUS (E090027) Modification Application – February 6, 2013

mobile terminal can determine what transmission frequencies are available for use. The
operating frequencies may be changed by command from the gateway stations. Also, a mobile
terminal can only transmit when its receiver is locked onto a CMDC forward link.

        The network management function of the CMDC network is provided by CMDC’s 24/7
Network Operations Center in Germantown, MD. This function includes monitoring traffic,
setting and adjusting operating frequencies, and activating a system wide shut-down capability
for individual or multiple service regions as required. The shut-down can be accomplished by
either CMDC personnel, locally or remotely, as well as by the satellite operator.


Compliance with Section 25.136(d)

       The following paragraphs explain CMDC’s compliance with Section 25.136(d) of the
Commission’s Rules, which address the protection of maritime mobile-satellite service distress
and safety communications in the lower L-band.

       Section 25.136(d)(1). All MES transmissions shall have a priority assigned to
       them that preserves the priority and preemptive access given to maritime distress
       and safety communications sharing the band.

        This requirement is not applicable, as CMDC’s MESs operate only on dedicated channels
that are not shared with any distress or safety communications.

       Section 25.136(d)(2). Each MES with a requirement to handle maritime distress
       and safety data communications shall be capable of either: (i) recognizing
       message and call priority identification when transmitted from its associated LES
       or (ii) accepting message and call priority identification embedded in the message
       or call when transmitted from its associated LES and passing the identification to
       shipboard data message processing equipment.

        This requirement is not applicable, as CMDC’s MESs are not required to handle distress
or safety communications.

       Section 25.136(d)(3). Each MES shall be assigned a unique terminal
       identification number that will be transmitted upon any attempt to gain access to
       a system.

        CMDC’s terminals comply with this requirement. Each CMDC MES is part of a virtual
private network with a distinct identity.

       Section 25.136(d)(4). After an MES has gained access to a system, the mobile
       terminal shall be under control of a LES and shall obtain all channel assignments
       from it.


                                                     Comtech Mobile Datacom Corporation
                                                                           FCC Form 312
                                                                         Exhibit D, Page 4
                               ROUS (E090027) Modification Application – February 6, 2013


       CMDC’s terminals comply with this requirement. After connecting to an associated LES
system, the CMDC MESs obtain control and frequency tuning commands over the
communication channel only from that LES.

       Section 25.136(d)(5). All MESs that do not continuously monitor a separate
       signalling channel or signalling within the communications channel shall monitor
       the signalling channel at the end of each transmission.

       CMDC’s terminals comply with this requirement. The CMDC MESs are a half-duplex
RF system operating on dedicated channels and when not transmitting are continuously
monitoring the LES for command signals.

       Section 25.136(d)(6). Each MES shall automatically inhibit its transmissions if it
       is not correctly receiving separate signalling channel or signalling within the
       communications channel from its associated LES.

        CMDC’s terminals comply with this requirement. As noted previously, a CMDC MES
will not transmit unless it is properly receiving and locked onto the incoming RF signal from its
associated LES.

       Section 25.136(d)(7). Each MES shall automatically inhibit its transmissions on
       any or all channels upon receiving a channel-shut-off command on a signalling
       or communications channel it is receiving from its associated LES.

       CMDC’s terminals comply with this requirement. A CMDC MES will not transmit if it
has been disabled by a control signal from the associated LES.

       Section 25.136(d)(8). Each MES with a requirement to handle maritime distress
       and safety communications shall have the capability within the station to
       automatically preempt lower precedence traffic.

        This requirement is not applicable, as CMDC’s MESs are not required to handle distress
or safety communications.


                                                    Comtech Mobile Datacom Corporation
                                                                          FCC Form 312
                                                                        Exhibit D, Page 5
                              ROUS (E090027) Modification Application – February 6, 2013


Compliance with NTIA/FAA Letter Requirements

       The following paragraphs explain CMDC’s compliance with the requirements set forth in
the enclosure to the NTIA/FAA Letter. These requirements address the protection of aeronautical
mobile-satellite service distress and safety communications in the upper L-band.

       1. All MES transmissions shall have a priority assigned to them that preserves
       the priority and preemptive access given to aeronautical distress and safety
       communications sharing the band.

        This requirement is not applicable, as CMDC’s MESs operate only on dedicated channels
that are not shared with any distress or safety communications.

       2. Each MES with a requirement to handle distress and safety data
       communications shall be capable of recognizing message and call priority
       identification when transmitted from its associated LES.

        This requirement is not applicable, as CMDC’s MESs are not required to handle distress
or safety communications.

       3. Each MES shall be assigned a unique terminal identification number that will
       be transmitted upon any attempt to gain access to a system.

        CMDC’s terminals comply with this requirement. Each CMDC MES is part of a virtual
private network with a distinct identity.

       4. After an MES has gained access to a system, the mobile terminal shall be
       under control of an LES and shall obtain all channel assignments from it.

       CMDC’s terminals comply with this requirement. After connecting to an associated LES
system, the CMDC MESs obtain control and frequency tuning commands over the
communication channel only from that LES.

       5. All MESs that do not continuously monitor a separate signalling channel shall
       have provision for signalling within the communications channel.

       CMDC’s terminals comply with this requirement. The CMDC MESs are a half-duplex
RF system operating on dedicated channels and when not transmitting are continuously
monitoring the LES for command signals.


                                                     Comtech Mobile Datacom Corporation
                                                                           FCC Form 312
                                                                         Exhibit D, Page 6
                               ROUS (E090027) Modification Application – February 6, 2013

       6. Each MES shall automatically inhibit its transmissions if it is not correctly
       receiving a separate signalling channel or signalling within the communications
       channel from its associated LES.

        CMDC’s terminals comply with this requirement. As noted previously, a CMDC MES
will not transmit unless it is properly receiving and locked onto the incoming RF signal from its
associated LES.

       7. Each MES shall automatically inhibit its transmissions on any or all channels
       upon receiving a channel-shut-off command on a signalling or communications
       channel it is receiving from its associated LES.

       CMDC’s terminals comply with this requirement. A CMDC MES will not transmit if it
has been disabled by a control signal from the associated LES.

       8. Each MES with a requirement to handle distress and safety-related
       communications shall have the capability within the station to automatically
       preempt lower precedence traffic.

        This requirement is not applicable, as CMDC’s MESs are not required to handle distress
or safety communications.


Compliance with NTIA interpretation regarding real time access and priority preemption

        As noted previously, NTIA has indicated that it will consider a terminal to satisfy the real
time 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 three (3) seconds. CMDC interprets this benchmark as meaning that each MES for all of
its operating modes must, within three (3) seconds of receiving a shutdown command or losing
lock on the downlink, stop all ongoing RF transmissions and prevent any new RF transmissions.

         In Alaska and Hawaii, CMDC’s MTM202 is programmed to operate at ¼ data rate. The
data rate is set by CMDC’s signal set and not by the individual operating the terminal. Operation
at a slower data rate is necessary in these locations to compensate for the reduced availability of
satellite bandwidth in these locations. At ¼ data rate, the transmission duration for a full length
message (128 bytes) from a MTM202 is 1.6 seconds.

        The MTM202 incorporates a two-second timeout parameter. The two-second timeout
parameter means that when a MTM202 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. As such, these
MESs require a maximum of 3.6 seconds outside of CONUS to stop all ongoing transmissions


                                                    Comtech Mobile Datacom Corporation
                                                                          FCC Form 312
                                                                        Exhibit D, Page 7
                              ROUS (E090027) Modification Application – February 6, 2013

and prevent any new transmissions. All other CMDC METs, including the MTM202 when
operated in CONUS, satisfy the NTIA shutdown requirement.


Waiver Request

        Section 1.3 of the Commission’s Rules authorizes the Commission to waive its rules for
“good cause shown.”4 In general, the Commission will grant a waiver of its rules if the relief
requested would not undermine the policy objective of the rule in question and would otherwise
serve the public interest.5 CMDC submits that the waiver requirements of Section 1.3 are
satisfied in this case for the following reasons.

       First, CMDC’s waiver request satisfies the requirements of the NTIA 2009 Letter for a
waiver. Per the NTIA 2009 Letter, an applicant can be authorized under a two-year waiver to
operate METs that do not satisfy the three-second shutdown requirement if the total number of
non-compliant METs is less than 10,000 and the applicant agrees to submit an analysis of its
MET operations in the U.S. showing the number of packets each month that exceed three (3)
seconds in duration.6 Those requirements are satisfied here. There are only about 900 MTM202
METs in existence today, and no additional MTM202s are being built.7 CMDC requests a two-
year waiver (as noted previously) and accepts a condition to submit a packet length analysis.

        Second, the Commission’s prior actions with respect to CMDC’s half-duplex terminals
provide precedent for grant of this waiver request. In the CMDC Order, the Commission granted
CMDC 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 with respect to the operation of certain half-duplex
terminals on MSAT-1 and MSAT-2 on the basis that (a) CMDC’s half-duplex terminals will not
adversely affect current aeronautical and maritime safety operations in the L-band; (b) CMDC
operates on dedicated channels; and (c) the extent and number of the operations that do not meet
NTIA’s shutdown requirements are limited.8 The Commission found that “under these
circumstances, requiring [CMDC] to terminate those limited operations … or to employ an
alternative (and more expensive) full-duplex system for those operations, or to employ a full-
duplex system for all of the systems because of the limited noncompliance of a few stations on a
few occasions, would impose an undue economic burden in light of the absence of harm in this
case.”9
4
       47 CFR § 1.3.
5
       See Comtech Mobile Datacom Corp., Order and Authorization, IB File No. SES-AMD-
       20070907-01251, DA 09-906, rel. May 15, 2009 (“CMDC Order”) at ¶ 4.
6
       See NTIA 2009 Letter at 4.
7
       The MTM202 is at end of life; while CMDC is selling units in stock, it is not building
       any new units.
8
       CMDC Order at ¶ 7.
9
       CMDC Order at ¶ 7.


                                                     Comtech Mobile Datacom Corporation
                                                                           FCC Form 312
                                                                         Exhibit D, Page 8
                               ROUS (E090027) Modification Application – February 6, 2013


         All of the findings on which the Commission based its decision to grant a waiver in the
CMDC Order are equally valid with respect to the continued operation of CMDC’s MTM202
terminals on SkyTerra 1, the MSAT satellites, and ISAT. As noted previously, there are a
limited number of MTM202 terminals in existence today. Worst case, each MTM202 terminal
takes only 3.6 seconds to stop all ongoing transmissions and prevent any new transmissions –
only 0.6 seconds longer than the NTIA requirement. An analysis of CMDC’s MET operations
over the 15-month period between September, 2011, and December, 2012, shows that, on
average, the monthly number of packets having a transmission duration exceeding three (3)
seconds is only twenty-nine (29) or 0.0644 per day, on average, assuming a 30-day month.
These data indicate that the likelihood that a single packet exceeding three (3) seconds is
transmitting during any second of the day is no greater than 0.0000027. Even during the month
with the most number of packets exceeding three seconds in duration, October 2012 with sixteen
(16), the number of packets having a transmission duration exceeding three (3) seconds is only
0.5333 per day, on average, assuming a 30-day month. These data indicate that the likelihood
that a single packet exceeding three (3) seconds is transmitting during any second of the day is
no greater than 0.0000222.

        All the MTM202 terminals operate on dedicated channels transmitting only short bursts
of data and using dedicated frequencies that are not assigned to and cannot cause interference to
services provided in the GMDSS or the AMS(R)S. CMDC notes that it has never received any
complaints of interference regarding the operation of any of its half-duplex METs, nor is CMDC
otherwise aware that any of its half-duplex METs have caused such interference. As such, the
Commission’s conclusion in the CMDC Order that a grant of CMDC’s requested waiver would
not result in any harmful or undue interference to aeronautical and maritime safety operations in
the L-band remains valid and supports grant of this waiver request.

        Third, grant of this waiver request will serve the public interest, as it will enable CMDC
to continue to satisfy customer demand for service. 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 METs in the U.S. and worldwide. Grant of this
waiver request will enable the U.S. Army to continue using their MTM202 METs, and will
permit CMDC to continue to provide requested services to the U.S. Army. Requiring CMDC to
terminate these operations or deploy alternative equipment would impose an undue economic
burden in light of the circumstances.

       Finally, as noted previously, CMDC’s MTM202 METs currently operate outside of
CONUS on SkyTerra 1, the MSAT satellites, and ISAT pursuant to a waiver identical to that
requested herein. As a practical matter, this waiver request merely seeks an extension of
CMDC’s existing waiver.

       In light of these facts, it is clear that there is good cause for grant of CMDC’s waiver
request. CMDC respectfully asks that the Commission grant this request.



Document Created: 2013-02-06 14:37:48
Document Modified: 2013-02-06 14:37:48

© 2024 FCC.report
This site is not affiliated with or endorsed by the FCC