Globalstar and Iridium satellite networks were tested in Camas, Washington in November and December 2015. Voice calls on Globalstar averaged 40 minutes in length while Iridium calls averaged 20 minutes. A 500KB file was transmitted over Globalstar in 8 minutes 30 seconds at a rate of around 8.5 kbps, meeting expectations. Issues were encountered with Iridium voice call drops and texting, and data speeds were found to be significantly slower than advertised.

1. Testing of Globalstar & Iridium satellite networks.
Camas, Washington. Nov. & Dec. 2015
Purpose of Voice Calls:
1.) Observe maximum possible duration of voice
calls on Iridium & Globalstar satellite phones
under optimal conditions.
Purpose of Data Call:
1.) Measure actual data speed of Globalstar 1700
handheld satellite phone in portable docking kit
under optimal conditions.

2. Satellite Phone Test Location. Camas, Washington.
View to all sides of horizon. Nov. & Dec. 2015.

3. 4 Globalstar Phones Used
3 1700 Handheld Phones & Portable
Docking Kit w/ helix antenna (white antenna on right).
#’s 254-219-6929, 254-219-7038, 907-928-1365.
1 2900 fixed “tactical” phone
w/ RJ11 jack.
Phone # 254-240-9077.

4. Sample of Globalstar voice calls
(Globalstar phones do not broadcast caller ID.)

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Globalstar Voice Calls. Test Results.
4 ½ hours of Globalstar satellite constellation sampled for voice calls.
Average length of maximum attainable Globalstar voice call was 40 min.

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Iridium Voice Calls. Test Results.
2 hours of Iridium satellite constellation sampled for voice calls.
Average length of maximum attainable Iridium voice call was 20 minutes.

7. • Portland area works in favor of Globalstar customer from QoS perspective
• ~ 45° North Lat. is nearly ideal location for optimal satellite visibility
• Relatively close proximity to gateway in High River, Alberta
• Average length of all Globalstar voice calls was 40 minutes.
• Overall, performance of Globalstar Generation 2 satellite system was “very
good / excellent” for voice & data applications.
• 1st voice call lasted 1 ½ hours.
• The times & days of all Globalstar calls were made at random.
• In 1 case after G* call drop, took ~ 5 min. to reacquire satellite & register
• Results of the Globalstar calls were within the range of expectations.
Observations from Globalstar Voice Calls
Artists rendition of Globalstar Gen. 2 satellite

8. Observations from Iridium Voice Calls.
• Portland area expected to produce high Quality of Service perspective.
• Longitude of `149W. Likely on same N/S orbital plane
of the 1 available gateway in Tempe, AZ.
• Average length of all Iridium voice calls was 20 minutes.
• Overall, performance of Iridium system was “good/fair” for voice applications.
1st call lasted 52 minutes, w/ stable signal.
• However, 3 of the 6 calls dropped under 10 minutes (under ideal conditions.)
• Quick re-acquisition of satellite after dropped calls suggest:
• Satellites were likely overhead at time of call drop (as opposed to a gap
in satellite coverage).
• If an Iridium satellite was present when the calls
dropped, suggests its possible not all 48
beams in Iridium footprint performing to full potential.

9. 911 test on Iridium
1. Was very problematic. Ultimately call did process, but experience was “a hassle”.
2. Had to change settings in phone to enable 911, otherwise would not process calls.
3. How will customers react in emergency situations?
4. How will customers reset phone back to original settings for dialing to PSTN/cellular
destinations?

10. Iridium texting test
• Could not get text message to send without referring to user manual.
• Service is possible, but lacks intuitive element when compared to sending text on iPhone

11. Globalstar Data Test.

12. • Used Globalstar satellite phone 907-928-1365 in portable docking kit.
• Sent 500KB file w/out compression software to preserve integrity of results.
• #777 packet data connection. Call routed directly into Internet at gateway.
• Data flow generally begins with 5 seconds upon establishment of call.
• File was PDF format. 25 pg. in length. Mostly text. Some pictures &
illustrations.
Globalstar Data Test
Actual file transmitted & Globalstar phone w/ docking kit used for test
Illustration of Globalstar packet data routing sequence.

13. • 25 pg. document transmitted in 8 min. 30 seconds.
• Same file would take 35 minutes on Iridium single-channel device
• Globalstar’s actual throughput demonstrated was
~ 8.5 kbp/s, slightly less than advertised 9.6 kbp/s.
• Actual throughput consistent w/ expectations due to
“overhead” inherent in data calls. Overhead could include
TCP/IP headers, PPP/MLPP headers, & encoding.
Globalstar Data Test Results. Transmitting 500KB file.
Actual file transmitted w/ GSP 1700 phone.

14. Thoughts on Iridium Data Services.
• Iridium encouraging Internet browsing is a
rather dubious assertion even with
compression technologies, considering the
raw bandwidth of 2.4kbp/s. In my previous
experiences, web browsing on IRDM:
• ~possible at all, in real-world situation?
• When real-time data exchange is
required by the Federal Government
• Practical?
• Financially prudent?
• Opening an Internet page on IRDM on
occasion will time out due to extremely
slow speed.
• Low bandwidth, frequent interruptions &
high airtime costs make Iridium packet data
cumbersome, time consuming & expensive.
Iridium data advertisement encouraging web browsing.

15. Thoughts on Iridium Pilot.
• Pilot is advertised as “broadband data” w/ uncompressed
speed up to 134 kbp/s.
• ITU classifies satellite based broadband data as
minimum 256kbp/s
• Technical specifications & FCC certification documents
state that Pilot consists of 14 multiplexed Iridium modems of 2.4 kbp/s bandwidth.
• Max possible bandwidth assuming multiplexing is 100% efficient would be 33 kbp/s.
• Numerous studies confirm multiplexing technology used for Iridium modems
~ 90% efficient.
• Realistically, bandwidth is no more than 30 kbp/s.
• Why would Iridium resellers “believe” uncompressed speeds up to 134 kbp/s are
possible on the Pilot ?

17. Iridium & Globalstar Network Testing carried out by
Donnie Hatch.
For additional questions, pls. contact at:
donniehatch@comcast.net
Tel 503-307-5489
Camas, Washington