Recommendation itu-r f. 1499 radio transmission systems for fixed broadband wireless access based on cable modem standards




Yüklə 291.49 Kb.
səhifə1/8
tarix16.04.2016
ölçüsü291.49 Kb.
  1   2   3   4   5   6   7   8

Rec. ITU-R F.1499


RECOMMENDATION ITU-R F.1499

RADIO TRANSMISSION SYSTEMS FOR FIXED
BROADBAND WIRELESS ACCESS BASED
ON CABLE MODEM STANDARDS

(Questions ITU-R 215/8 and ITU-R 140/9)

(2000)

Rec. ITU-R F.1499
CONTENTS
Page

Introduction 3

Scope 3

References 3



Definitions and abbreviations 6

Conventions 11

Considerations 11

Recommendation 11

1 General system requirements 11

1.1 Service goals 11

1.2 Reference architecture 12

1.3 Categories of interface specification 12

1.3.1 Phase 1 12

1.3.2 Phase 2 12

1.3.3 Phase 3 12

1.3.4 Phase 4 12

1.4 Server location 14

2 Functional assumptions 14

2.1 BWA network 14

2.2 Equipment assumptions 14

2.2.1 Frequency plan 14

2.2.2 Compatibility with other services 14

2.2.3 Fault isolation impact on other users 14

2.3 RF channel assumptions 14

2.3.1 Transmission upstream and downstream 15

2.4 Transmission levels 15

2.5 Power control requirements 15

2.6 BER vs. S/N specifications 15

2.7 Frequency inversion 15

3 Communication protocols 17

3.1 Protocol stack 17

3.1.1 BWA CPE and BWA BTS modems as hosts 17

3.1.2 Data forwarding through the BWA CPE and BTS modems 18

Page

3.2 The MAC forwarder 21

3.2.1 Example rules for data-link-layer forwarding 22

3.3 Network layer 22

3.4 Above the network layer 22

3.5 Data link layer 23

3.5.1 LLC sublayer 23

3.5.2 Link-layer security sublayer 23

3.5.3 MAC sublayer 23

3.6 PHY layer 24

3.6.1 Downstream transmission convergence sublayer 24

3.6.2 PMD sublayer 24

4 PMD sublayer specification 24

4.1 Scope 24

4.2 Upstream 25

4.2.1 Overview 25

4.2.2 Modulation formats 26

4.2.3 FEC encode 29

4.2.4 Scrambler (randomizer) 29

4.2.5 Preamble prepend 29

4.2.6 Burst profiles 29

4.2.7 Burst timing convention 32

4.2.8 Transmit power requirements 32

4.2.9 Fidelity requirements 34

4.2.10 Frame structure 36

4.2.11 Signal processing requirements 37

4.2.12 Upstream receiver input power characteristics 37

4.2.13 Upstream electrical output from the BWA CPE modem 38

4.3 Downstream 39

4.3.1 Downstream protocol 39

4.3.2 Scalable interleaving to support low latency 39

4.3.3 Downstream frequency plan 39

4.3.4 BWA BTS output electrical 39

4.3.5 Downstream RF input to BWA CPE 40

4.3.6 BWA CPE modem BER performance 40

5 Downstream transmission convergence sublayer 41

5.1 Introduction 41

5.2 MPEG packet format 42

5.3 MPEG header for BWA data-over-the-air 42

5.4 MPEG payload for BWA data-over-the-air 43

5.5 Interaction with the MAC sublayer 43

5.6 Interaction with the PHY layer 44

5.7 MPEG header synchronization and recovery 44

6 MAC specification 45

Annex 1 – Data-over-BWA interface documents 45

Introduction


Local access and other high density radio-relay service planning and system deployments have rapidly accelerated in the last few years in many countries. This acceleration is due in large part to the trend towards increased demand and competition in the provision of high bit-rate local telecommunications and video distribution services. Because of cost and speed of deployment considerations, these developments are placing a major new focus on the provision of services directly to end users via fixed wireless access systems (FWA).

Current broadband wireless access (BWA) data rates over individual circuit paths range from about 1.5 Mbit/s to about 45 Mbit/s, and are expected to reach at least 310 Mbit/s within the next few years, as radios utilizing higher order modulation schemes become available (see Recommendation ITU-R F.758).

The variety of possible broadband FWA network configurations includes: conventional point to point (P-P), conventional point-to-multipoint (P-MP), and combinations thereof, e.g. P-P systems deployed in multi-sectored P-MP configurations. High density deployment of independent P-P links similarly results in clusters that assume the essential characteristics of P-MP deployment. An emerging system architecture is that of multipoint-to-multipoint (MP-MP), similar to mesh systems.

These broadband FWA systems are predominantly deployed in dense urban, suburban, and campus environments where transmission path elevation angles may reach up to about 40 to 60. Links are regularly deployed on an on-demand basis to meet specific end-user requirements as they develop.

This Recommendation addresses fixed BWA systems, and this is based on ITU-T Recommendation J.112, Annex B – Data over cable radio frequency interface. A number of frequency bands in the range 2.5-66 GHz can be appropriate for these systems. This and other systems, which may be addressed in other recommendations, belong to the category of multimedia wireless systems (MWS). MWS are wireless systems which support information exchange of more than one type, such as text, graphics, voice, sound, image, data and video.

This Recommendation is complementary to ITU-T Recommendation J.116. This Recommendation and ITU-T Recommendation J.116 should be considered in their totality when implementing BWA systems.


Scope


This Recommendation is based on the standards approved and published by ITU-T for cable modems (specifically ITU T Recommendation J.112, Annex B), but adapts the technical parameters for use in the wireless access environment, that is for BWA customer premises equipment (CPE) modems. The commonality is maximized to achieve economies of scale.

This Recommendation is complementary to ITU-T Recommendation J.116. This Recommendation and ITU-T Recommendation J.116 should be considered in their totality when implementing BWA systems.


  1   2   3   4   5   6   7   8


Verilənlər bazası müəlliflik hüququ ilə müdafiə olunur ©azrefs.org 2016
rəhbərliyinə müraciət

    Ana səhifə