(Continuation of Question 16/13 studied during 1997-2000)

Background and justification

Transmission error and availability performance objectives and allocation methods are needed to support efficient design of digital networks and associated transmission equipment, and to provide guidance to developers of related systems and applications. Furthermore, transmission error and availability performance needs to be related to customer applications supported by digital networks.

Items for study

1. What provisions should be made to keep Recommendations specifying transmission error and availability performance up to date in a changing technical environment considering new interfaces or technologies?

2. How can Recommendation G.821 be reconciled with respect to the points of inconsistency identified in Appendix I of that Recommendation? (See also the Attachment to this Question containing a proposal for a new Recommendation.)

3. How shall Recommendation G.826 be modified to take into account new Recommendation G.828?

4. What further availability performance objectives should be specified in Recommendations G.827 and G.827.1 on the basis of the observed performance of path elements?

5. Is there a need to merge G.827 and G.827.1?

6. What additional error performance parameters and objectives need to be recommended with regard to:

a) IP-supported services?

b) B-ISDN applications?

c) ATM requirements?

d) Requirements resulting from the deployment of optical channels? Studies would include, e.g. definition of error and availability performance parameters and objectives applicable to Wavelength Division Multiplex (WDM) systems including Dense Wavelength Division Multiplex (DWDM)

e) Requirements applicable to high bit rates, e.g. STM-256?

f) Requirements from mobile systems, e.g. IMT-2000?

7. How can the transmission error objectives specified in Recommendation G.828 be related quantitatively to the cell layer performance observed in ATM networks, and the packet layer performance observed in IP networks, that are supported by SDH equipment?

8. What provisions should be made to deal with the particular characteristics of various digital transmission systems, e.g., optical transmission systems, satellites, radio-relay systems, mobile-satellite systems?

9. What provisions should be made to take into account the influence of access systems on error performance?

Specific tasks with deadlines

• Recommendation G.821.1: new version in 2001
• Recommendation G.826: revised version in 2002
• Recommendation G.827: revised version in 2002
• Recommendation G.827.1: revised version in 2002
• Recommendation G.828: revised version in 2003
• Recommendation G.829: revised version in 2003
• Recommendation G.optperf: new Recommendation in 2002

Relationships

• ITU-T Study Groups on transmission system maintenance
• ITU-T Study Groups on transport systems and equipment
• ITU-R Study Groups on satellite systems
• ITU-R Study Groups on fixed radio systems