Conclusion

Date: 2015-10-07; view: 491.

Memory and processing power

Optical switching

The use of optical switching, together with various forms of Wave­length Division Multiplexing (WDM), will lead to a requirement for yet another layer in the SDH hierarchy beyond the STM section layer. Real high speed optical switching, together with wavelength conversion is still some way in the future, hence there is no pressure to extend SDH at present.

As soon as it becomes economically feasible, more memory and processing power will be installed in individual SDH network elements. The use of this capability to support ever larger blocks of software will results in the average software download action trans­ferring ever more bytes, thus putting a strain on the Embedded Communication Channels (ECCs) that are built into the STM SOHs. There is also the chance that larger quantities of more sophisticated element control software will result in more management traffic between network elements and between elements and their control­lers, further increasing the load on the existing ECCs. Thus, at some point in the future is very likely that the SDH standards will have to be altered to expand the capacity of the ECCs beyond their current rates of 192 and 576kbit/s.

SDH is here to stay as the dominant public network transmission standard of this decade. However, the effects of the full range of SDH standards will probably be felt over a much wider area of telecommunications, because of their general applicability. For example the mere existence of the SDH optical interface specifica­tions will probably lead to their use in a variety of non-SDH applications, simply because there is a dearth of competing stand­ards. Another example is that of the SDH network recommendations, G.SNA1/2, which, with relatively little modification, are applicable to a wide variety of non-SDH networks, in particular, plesiochronous networks.

1. Learn the following technical words and word-combinations:

47.2

42.7.1

42.7.2

42ю7ю3

42.8.1

42.8.2

42.8.3

42.8.4

42.8.5

Exercise 2 Read the text 42.7- 42.9

Exercise 3 Find the Russian equivalents for the following English technical word-combinations:

Exercise 4

Find the English equivalents for the following Russian technical word-combinations:

Exercise 5

Answer the following questions:

1.Does SDH currently have any real competitors?

2.What is ATM standard aimed at?

3.What are several other Fast Packet techniques aimed at?

4.What is the best way to view Frame Relay?

5.Why can a Frame Relay network deliver much higher throughputs than an X.25 network?

6.What is Switched Multimegabit Data Service aimed at?

7.What are some problems, relating to the maximum delay that an FDDI ring can withstand?

8.What will equipments implementing the SDH standards be strongly influenced by?

9.What does faster, smaller and cheaper traffic handling lead to?

10.What are the advantages to optical interconnection?

11.What devices are used to increase the maximum distance between transmitter and receiver?

12.Does the extinction of line system repeaters mean that the SDH RSOH in the STMs will eventually become redundant for terrestrial systems?

13.Is there any pressure to extend SDH at present?

Exercise 6

Make a short report on perspectives of memory and processing power (part 42.8.5)

Exercise 6

a) Translate into Russian in writing part 42.8.1,42.8.2 and 42.8.4.

b) Translate into Russian in writing part 42.8.3.