Radio Technical Commission for Maritime Services



Radio Technical Commission for Maritime Services

1800 N. Kent St., Suite 1060

Arlington, Virginia 22209-2109

hq@

Telephone: +1-703-527-2000 Telefax: +1-703-351-9932

August 28, 2007

SUMMARY RECORD

Meeting of RTCM Special Committee 123

Standards for VHF-FM Digital Small Message Services

Time / Dates: 1:00 p.m. Thursday, September 20, 2007

Location: RTCM Headquarters

(for directions see )

AGENDA

1. Call to order, introduction of attendees, and approval of agenda

Mr. Norsworthy opened the meeting. The agenda (paper 160-2007-SC123-035) was approved. The following were in attendance:

|NAME |AFFILIATION |TELEPHONE |E-MAIL |

| | |FAX | |

|Ross Norsworthy | REC, Inc. |+1 727 515-8025 |Ross_Norsworthy@ |

| | |fax: +1 727 593-7396 | |

|John Flood |ACR Electronics |+1 954-981-3333, ext 124 |jflood@ |

| | |fax: +1 954-983-5087 | |

|Daoud Serang |CML Microcircuits (USA) Inc. |+1 336 744-5050 |dserang@ |

| | |fax: +1 336 744-5054 | |

|Ghassan Khalek |FCC |+1 202 418-2771 |ghassan.khalek@ |

| | |+1 202 418-2643 | |

|John Bourke |Harris Corp. |+1 321 726-1412 |jbourke@ |

|Masaaki Takahashi |ICOM America |+1 425 450-6043 |masaakitakahashi@ |

| | |fax: +1 425 454-1509 | |

|Bob Markle |RTCM |+1 703 527-2000 |rmarkle@ |

| | |fax: +1 703 351-9932 | |

|Charlie Zaloom |Sea Smart |+1 631 765-3660 x3139 |Charlie@ |

|Mark M. Johnson |Shine Micro |+1 360 437-2503 |mark@ |

| | |cell: +1 360 643-3176 | |

|Joe Ryan |The Skip’r LLC |+1 757-480-2285 |jryan@ |

| | |fax: +1 757 480-2287 | |

|Laura King |USCG Command & Control Engineering Center|+1 757 295-2265 |laura.e.king@uscg.mil |

2. Approval of summary record of previous meeting (Paper 157-2007-SC123-032)

The summary record was approved as written.

3. Intellectual Property Rights issues (just keeping a watchful eye)

There are no IPR issues at present.

4. Review new input papers

The committee reviewed the following papers and related issues:

• 159-2007-SC123-034

• 158-2007-SC123-033

There was an extended discussion on relevant data protocols, including 43 Kb/sec π/4 DQPSK and 9.6 Kb/sec GMSK AIS-type transmissions. The faster data rate provides for more data transfer in a period of time, but AIS type transmissions provide extended range. However, concern was expressed over the reliability of the type of access scheme under consideration, over long ranges.

There was also discussion concerning whether or not the data service under consideration would meet the regulations of the U.S. Federal Communications Commission, or if some type of rule change or waiver would be required. Mr. Serang volunteered to research the issue.

Mr. Ryan noted that this committee is working on a VHF SMS service, and that we should not try to extend the range far beyond typical VHF range. If long range services are required, then an MF/HF solution is required, which is beyond the terms of reference of SC123. Therefore, extending the range should not be part of the discussion. The issue should be efficient use of the band. Mr. Serang moved that the functional scope of the SC123 work be limited to VHF SMS service in the normal VHF range, since we have not been able to move forward while that is unresolved. Mr. Norsworthy recalled the discussion of the RTCM Board on the subject, and that there should also be a way forward for the GMSK solution. It may already be permitted under current FCC rules. In any case, the motion was carried without objection with the understanding that the GMSK solution could be considered as an AIS binary messaging solution.

Reliability of communication was discussed. Forward Error Correction was considered to be essential. An ACK could also be required. If we use AIS Message 26 to set up the data transfer, that message could specify whether an ACK is required.

There was a discussion on the use of the U.S. broadcasters' VHF channel white space. The broadcasters are apparently opposed to use of this spectrum by mobile users, but might not object to fixed stations. Mr. Norsworthy noted that in any one port area, not all of the channels are assigned, so there is unused capacity.

5. Relevant communication protocols

This discussion took place in the context of agenda item 4.

6. Preliminary standard outline and drafting

No progress was reported on the standard outline, pending progress on resolution of issues stated under agenda item 4 above.

7. ITU Working Party 8B Status Report and proposed new contributions

In the June 2007 meeting of WP8B (Working Party 8B), ITU approved a new ITU-R Report for assessing EMC in the e-NAV services (voice, data and AIS) in Appendix 18 (the marine VHF band) – See RTCM Paper 227-2007-SC123-039. A new ITU-R Recommendation for VHF data transmission was also approved that includes the 43.2 KBPS D8PSK transmission method recommended by RTCM SC123 – See RTCM Paper 228-2007-SC123-040. These two new ITU-R standards are planned to be published soon.

8. Based upon discussions under agenda items 3, through 7; development of the future work plan for SC123

The future work plan for SC123 should consider the two new ITU-R standards stated in agenda item 7. For GMSK/AIS transmission on other VHF non-AIS channels, the FCC was asked to address the question of whether this is permitted under current FCC rules.

9. Other business

No other business items were raised.

10. Assignment of Action Items for next meeting

a. Mr. Serang will prepare a paper for the next meeting on the issues concerning FCC permitted emission classes for the VHF marine band in 47 CFR Part 80.

b. Mr. Bourke will update the propagation study for the next meeting to include different levels (to account for both the 43.2 KBPS D8PSK and the GMSK/AIS transmission methods).

c. Mr. Khalek will report on whether the FCC believes that data transmission on VHF marine channels is already permitted under the current rules.

11. Date and Venue for next meeting:

December 6, 2007, 1:00 pm at RTCM Headquarters.

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