Motivation

The growth in demand for data services in small businesses and the home is driving telecommunications operators to provide high bandwidth connections to these customers. Because of the desire to reuse existing access networks (on cost grounds) new technical approaches generally involving spread spectrum techniques are being developed and implemented.

These techniques introduce a new family of EMC issues.

The following Recommendation, in force at the time of approval of this Question, falls under its responsibility:

• K.60.

Question

This question will study the impact of spread spectrum techniques and other modulation techniques on the electromagnetic environment. This question will produce one or more recommendations, which will allow telecommunication network operators to minimize the risk of interference to the user of the radio spectrum from these new access systems. In particular the question will study whether the increase in the probability of the existence of interfering signals generated by the spread spectrum nature of these systems is balanced by the reduction in the signal level at any specific frequency. Work will also review whether the dominant mechanisms of interference remain the same for these new systems. Topics such as dithered clocks and frequency may also be covered by this work.

As a second stream under the same question the validity of current immunity techniques (especially the need for broadband radiated and conducted tests) for these new systems will also be studied.

This question will also study the interference from the next generation access systems to existing or next generation telecommunication networks

Study items to be considered include, but are not limited to:

• Prediction method for emission from broadband signals transmitting in a cable, in particular in plural systems existing in a cable;
• EMC requirements and mitigation methodology for next generation access systems to existing or next generation telecommunication networks systems. An important issue is the possibility of interference from power-line broadband technologies (access Power Line Communication, PLC) to telecommunication access systems;
• Mitigation methodology for next generation access systems to existing or next generation telecommunication networks systems. Important issues are:
  • the possibility of interference from power-line broadband technologies (access Power Line Communication, PLC) to telecommunication access systems
  • the possibility of interference from power-line broadband technologies (access Power Line Communication, PLC) and telecommunication access systems to radio services.

Tasks

Tasks include, but are not limited to:

• One or more recommendations detailing appropriate EMC requirements for broadband access systems (including the consideration of the need for a separate broadband test method and emission level), considering in particular:
  • Evaluation methodology for radiated emissions from plural broadband access systems under unbundled condition and guidance for solving radio interference;
  • Characterization of the radiated disturbances from broadband services;
  • Evaluation of interference from power-line broadband technologies (access Power Line Communication, PLC) to telecommunication access systems;
• Maintenance and enhancement of the Recommendation K.60.
  An up-to-date status of work under this Question is contained in the SG 5 Work Program (use URL as shown in the table below).

Relationships

Recommendations:

• K-series

Questions:

• 1, 10, 12 and 16/5

Study Groups:

• ITU-T SG 15
• ITU-R SG 1

Standardization bodies:

• IEC CISPR