EU, U.S. split over Galileo M-code overlay

GPS World, Dec, 2002

The United States and Europe remain at loggerheads regarding the proposed overlay of a Galileo publicly regulated service (PRS) signal on the portions of the L1 spectrum where the Pentagon plans to place a new military signal (M-code). During a presentation to a European conference in November, a U.S. representative characterized the Bush Administration's opposition to such an overlay as "non-negotiable."

Another development highlighting the NavSat 2002 conference is a concerted effort by the People's Republic of China to become a full partner in the Galileo program. A large delegation of Chinese technical personnel attended the event at the invitation of the European Space Agency (ESA). Olivier Onidi, head of unit for Galileo and intelligent transport in the European Commission Directorate-General for Transport and Energy, says the European leaders "hope to issue very soon a formal mandate for negotiations with China to establish concrete cooperation" on the Galileo program.

Despite the M-code overlay dispute, bilateral discussions between working groups filled with technical experts from both sides reported substantial progress in addressing issues of compatibility and interoperability between GPS and the Galileo system under development by the European Union (EU) and ESA. The PRS/M-code overlay, however, was not among the items of agreement at the October 21-23 meeting of the working group in Washington, D.C.

At issue is the U.S. Department of Defense (DoD) desire to be able to jam other radionavigation signals in a theater of operation so as to provide an edge to allied users of military GPS receivers. This "selective denial" capability would be complicated by the presence of an encrypted PRS signal atop the M-code bands, because the U.S. could not jam the PRS without jamming its own signals.

The PRS is primarily intended for use by public safety organizations, including police, fire departments, ambulances, and security forces responsible for national borders. However, its use by European and allied military forces is not ruled out.

A related U.S. concern that PRS broadcasts could potentially interfere with GPS signals during regular operations appears to have been largely allayed by the results of research presented by European researchers in recent months.

A Non-Negotiable Position. The PRS/M-code dispute flared up during presentations at the November 12 plenary session of the NavSat 2002 conference held in Nice, France. Jason Kim, a U.S. Department of Commerce representative on the executive secretariat of the Interagency GPS Executive Board (IGEB), told the audience, "The U.S. government considers the assurance of compatibility as the primary requirement for the GPS user community." He defined compatibility as "the assurance that one GNSS [global navigation satellite system] will 'do no harm' to another GNSS by degrading the standalone services that it provides."

The new M-code signals are being developed to be spectrally separated from civil signals because without such separation, "security is weakened and greater degradation of civil service is likely." He concluded, "Overlay of M-code signals is not dual-service compatible and is unacceptable to the U.S." He later added, "The U.S. considers this matter to be non-negotiable."

This characterization of the U.S. position on the overlay issue is the strongest statement to date on the matter and drew an equally vehement response from several European speakers.

Rene Oosterlinck, head of the ESA Navigation Department and a plenary speaker, told the NavSat audience, "We do not accept the compatibility definition of the U.S. -- that if you can't jam a signal, it's not compatible. That is a political definition, not a technical one."

Oosterlinck said that the International Telecommunications Union (ITU) guidelines on interference do not incorporate the broader interpretation being made by the United States. The ITU hosts the World Radio Conference that regulates international use of spectrum and will hold its next meeting in 2003 at which various GPS and Galileo issues will be debated.

The United States has proposed that the issue of military use of the PRS be addressed by NATO. However, the membership of NATO does not coincide exactly with the membership either of the EU or of ESA.

Security Matters. A Galileo System Security Board (GSSB) is being convened under the Galileo Steering Committee that will oversee Security policy and procedures and define the interface between the steering committee and security/military organizations. John Davey, from the British Ministry of Defense, and Gen. Benoit Bescond, from the office of the French prime minister, co-chair the working group that is overseeing establishment of the GSSB. Bescond reportedly will discuss the PRS/M-code situation with NATO representatives in the near future.

The Chinese delegation at NavSat was headed by Shao Liqin, a department director in the Chinese Ministry of Science and Technology, and Cheng Pengfei, vice-president of the Chinese Academy of Surveying and Mapping. China has launched two geostationary satellites that provide test signals for the country's satellite navigation program. But in negotiations with ESA and individual European governments, the Chinese government has indicated a willingness to make a substantial financial contribution to Galileo in return for a substantial involvement in the system's development and operation.