Resource Management in Satellite Networks part 35 potx

Chapter 10: CROSS-LAYER METHODS AND STANDARDIZATION 329 techniques, especially in the return link for terminals with small antennas.. ITU is divided in three sectors: ITU-T that aims at

Chapter 10: CROSS-LAYER METHODS AND STANDARDIZATION 329 techniques, especially in the return link for terminals with small antennas The adoption of spectrum spreading is a possible solution to reduce the EIRP, while preserving the required SNR, at the expenses of reduced spectral efficiency In the forward link, the introduction of spreading requires the design of a new DVB-S2 receiver In the return link, each terminal could in principle implement direct spreading within the assigned time and frequency slot (MF-TDMA approach)

• Fading countermeasures: the more challenging propagation conditions of

the non-LoS scenario can be mitigated by adopting advanced techniques such as diversity and higher layer FEC schemes Moreover, new synchro-nization acquisition and maintenance procedures need to be employed to cope better with frequent fades

• Resource management techniques: efficient RRM schemes need to be

adopted to account for mobility, such as: impact of spreading on the MF-TDMA allocation process (DVB-RCS); support of handover requests with suitable protocols; interworking with terrestrial networks in shadowed areas (e.g., tunnels, cities, etc.) where gap fillers can be used; adaptive schedulin techniques for the forward link that are aware of the physical layer behavior

All these innovative aspects require a cross-layer system design aiming at optimizing the choices made at different layers The DVB-TM is now working

to specify the modifications that are needed for the mobile extension of the DVB-S2 standard [23] The SatNEx II project [24] is actively involved in this standardization process

DVB-H

The broadcast of digital television signals was originally targeted to fixed reception, although mobile reception is also feasible with current digital television standards (DVB-T, DVB-S2) The Commercial Module of DVB

decided to launch commercial requirements for the production of ad hoc

specifications able to provide broadcasting to one specific niche of the mobile

receivers: handheld terminals This is the aim of the DVB-Handheld (DVB-H)

standard

Conditional access is important in all broadcast radio/satellite networks

to prevent unauthorized access to the broadcast content by eaves-dropping

In DVB-H, an IP-based Conditional Access System (IP-CAS) can provide

link-layer encryption (scrambling) for DVB-H services CAS messages are delivered over IP and may take advantage of time-slicing to save power at

a receiver The DVB common scrambling algorithm on Transport Stream

packets is also employed (DVB-CAS): it uses entitlement control messages to send keys to receivers and entitlement management mode messages to deliver

management messages

10.6.5 International Telecommunication Union

ITU is an international organization of the United Nations where governments and industries coordinate global telecom networks and services ITU is divided

in three sectors: ITU-T that aims at the definition of high-quality standards covering all fields of telecommunications; ITU-R that plays a fundamental role

in the management of the radio-frequency spectrum, physical layer issues, and

satellite orbits; and ITU-D, dealing with Telecommunications Developments.

ITU-R is charged with determining the technical characteristics and operational procedures for a huge and growing range of wireless services This Sector also plays a vital role in the management of the radio-frequency spectrum, a finite natural resource that is increasingly in demand due to the rapid development of new radio-based services and the enormous popularity

of mobile communication technologies

In its role as global spectrum coordinator, ITU-R develops and adopts

the Radio Regulations, a voluminous set of rules that serve as a binding

international treaty governing the use of the radio spectrum for different services around the world ITU-R also acts, through its Bureau, as a central

registrar of international frequency use, recording and maintaining the Master International Frequency Register, which currently includes around 1,265,000

terrestrial frequency assignments, 325,000 assignments servicing 1,400 satellite networks, and another 4,265 assignments related to satellite Earth stations Moreover, ITU-R is responsible for coordinating efforts to ensure that commu-nication, broadcasting and meteorological satellites in the world’s increasingly crowded skies can co-exist without causing harmful interference each other The Union facilitates agreements between both operators and governments, and provides practical tools and services to help frequency spectrum man-agers

The portion of the radio-frequency spectrum suitable for communications

is divided into ‘blocks’, the size of them varying according to individual services and their requirements These blocks are called ‘frequency bands’ and are allocated to services on an exclusive or shared basis The full list of

services and frequency bands allocated in different regions forms the Table of Frequency Allocations, which is a part of the radio regulations.

10.7 Conclusions

A range of cross-layer optimization techniques have been proposed and evaluated in this book for three different scenarios (i.e., DVB-S/DVB-RCS via GEO bent-pipe satellite, S-UMTS via GEO bent-pipe satellite, and LEO constellation with regenerating satellites) The most significant techniques have been summarized in this Chapter to provide final guidelines for both standardization efforts and further research directions

Cross-layer methods have been categorized, considering: (i ) either explicit

Chapter 10: CROSS-LAYER METHODS AND STANDARDIZATION 331 signaling or an implicit scheme with a joint optimization of different protocol

layers; (ii ) the definition at higher layers of requirements to be used for

ap-propriate settings at lower layers or, vice-versa, the lower layers progressively determining the requirements at higher layers As for explicit cross-layer, we have described different mechanisms for the exchange of internal protocol state information between non-adjacent protocol layers, thus violating the classical ISO/OSI layered philosophy

We have proved that the cross-layer techniques can improve the overall end-to-end quality of service, while optimizing the efficiency in utilizing the

scarce satellite radio resources However, standardization fora have not yet

significantly addressed cross-layer issues To this aim, there is a need for a new framework, as well as the strong cooperation of different standardization bodies One of the aims of this book has been to provide some useful insights that may promote new standardization activities on cross-layer air interface design for satellite communication networks

[1] J H Saltzer, D P Reed, D D Clark, “End-to-End Arguments in System

Design”, ACM Transactions in Computers Systems, Vol 2, No 4, pp 277-288,

November 1984

[2] P Karn, C Bormann, G Fairhurst, D Grossman, R Ludwig, J Mahdavi, G Montenegro, J Touch, L Wood, “Advice for Internet Subnetwork Designers”, BCP 89, IETF RFC 3819, July 2004

[3] S Floyd, V Jacobson, “Random Early Detection Gateways for Congestion

Avoidance”, IEEE/ACM Transactions on Networking, Vol 1, No 4, pp.

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Conference 2003 (IEEE WCNC 2003), New Orleans, USA, pp 1084-1089,

March 2003

[6] The Internet Engineering Task Force (IETF); Web page with URL: http://www.ietf.org

[7] European Telecommunications Standards Institute (ETSI); Web page with URL: http://www.etsi.org

[8] International Telecommunication Union; Web page with ULR: http://www.itu.int/home/index.html

[9] MoSSA, Advanced Satellite Mobile Systems-Task Force Specific Support Action, Project IST-507557, Deliverable “Survey on Standardization and Regulatory Activities”; Web site with URL: http://asms1.wss.bcentral.com/mossa/default.htm

[10] ETSI TC-SES working group; Web page with URL: http://portal.etsi.org/ses/

[11] ETSI, “Satellite Earth Stations and Systems (SES); Satellite Component of

UMTS/IMT2000; G-family; Part 1: Physical channels and mapping of transport channels into physical channels (S-UMTS-A 25.211)”, TS 101 851-1

[12] ETSI, “Satellite Earth Stations and Systems (SES); Satellite Component of

UMTS/IMT2000; G-family; Part 2: Multiplexing and channel coding

(S-UMTS-A 25.212)”, TS 101 851-2

334 G Fairhurst, M A V´azquez Castro, G Giambene

[13] ETSI, “Satellite Earth Stations and Systems (SES); Satellite Component of

UMTS/IMT2000; G-family; Part 3: Spreading and modulation (S-UMTS-A 25.213)”, TS 101 851-3

[14] ETSI, “Satellite Earth Stations and Systems (SES); Satellite Component of

UMTS/IMT2000; G-family; Part 4: Physical layer procedures (S-UMTS-A 25.214)”, TS 101 851-4

[15] ETSI, “Satellite Earth Stations and Systems (SES); Satellite Component of

UMTS/IMT2000; G-family; Part 5: UE Radio Transmission and Reception (S-UMTS-A 25.101)”, TS 101 851-5

[16] ETSI, “Satellite Earth Stations and Systems (SES); Satellite Component of

UMTS/IMT2000; G-family; Part 6: Space Segment Radio Transmission and Reception (S-UMTS-A 25.104)”, TS 101 851-6

[17] IST-MAESTRO project, “Mobile Applications & sErvices based on Satellite & Terrestrial inteRwOrking”; Web site with URL: http://ist-maestro.dyndns.org, 2006

[18] ETSI, “Evaluation of the OFDM as a Satellite Radio Interface Satellite Earth Stations and Systems (SES); Satellite Component of UMTS/IMT-2000”, TR

102 433, 2006

[19] Digital Video Broadcasting (DVB) Project; Web page with URL: http://www.dvb.org

[20] ETSI, “Digital Video Broadcasting (DVB); Interaction channel for Satellite Distribution Systems”, EN 301 790

[21] SatLabs official Web site with URL: http://www.satlabs.org/

[22] ETSI, “Digital Video Broadcasting (DVB); Second Generation Framing Structure, Channel Coding and Modulation Systems for Broadcasting, Interactive Services, News Gathering and other Broadband Satellite Applications”, EN 302 307

[23] S Scalise, G E Corazza, C P´arraga Niebla, P Chan, G Giambene, F Hu, A Vanelli-Coralli, M A V´azquez Castro, “Towards the Revision of DVB-S2/RCS

Standard for the Full Support of Mobility”, SSC Newsletter, Vol 17, No 2,

November 2006

[24] SatNEx II Web site with URL: http://www.satnex.org

Access protocol, 120, 132

Adaptive algorithms, 209, 295

Adaptive coding and modulation, 16,

24, 106, 139, 208, 316

Asynchronous transfer mode, 109

B

Broadband satellite multimedia, 28, 31,

69, 98, 256

Broadcast and multicast services, 5, 80,

152, 160

C

CAC, 45, 51, 100, 110, 177, 179, 184,

189, 199, 257

Complete partitioning, 52, 179

Complete sharing, 52, 179

Call handover, 53, 189, 195, 214, 233

Inter-satellite handover, 54, 190, 194,

214

Intra-satellite handover, 54, 190, 191,

214

CDMA, 14

Channel quality indicator, 138

Channel utilization, 162, 305

Combined free/demand assignment

multiple access, 48, 101, 256

Commercial solutions, 82, 89

Communications architecture, 314, 320

Cross-layer signaling, 320

Congestion control, 164, 186

Control-theoretic approach, 213

Cross-layer approach, 34, 156, 164, 256, 314

Bottom-up approach, 316 Hybrid approach, 317 Top-down approach, 316 Cross-layer design, 35, 36, 45, 96, 105,

214, 221, 256, 270, 313, 314 Explicit cross-layer, 35, 36, 133, 145,

156, 164, 300, 315 Implicit cross-layer, 35, 36, 45, 95,

217, 270, 290, 315, 317

D

Delayed real-time services, 83 Demand assignment multiple access, 18,

290, 298, 300 Access delay, 290, 298 Rate-based dynamic capacity, 20,

211, 221, 249, 299 Volume-based dynamic capacity, 20,

211, 221, 249, 299, 303 DiffServ, 36, 77, 107, 183, 246 DVB-S, 16, 80, 105, 187, 326 DVB-RCS, 17, 81, 186, 211, 249, 289,

298, 323, 327 Adaptive coding, 218 Implementation issues, 218, 228 MF-TDMA scheme, 15, 17, 184,

211, 251, 302, 327

E

ETSI TC SES S-UMTS working group,

15, 121, 325

336 Index

Explicit congestion notification, 107

F

FDMA, 13

G

GEO satellite systems, 4, 10, 68, 71,

125, 131, 141, 184, 209, 265, 290

H

Handover algorithms, 51

Handover queuing, 53

Predictive resource reservation, 54

HSDPA, 16, 108, 138, 139, 141, 144, 148

Hybrid satellite networks, 265

Erasure codes, 265

QoS, 266

WiFi networks, 267

I

Infinitesimal perturbation analysis, 99,

216, 257

IntServ, 36, 77, 107, 183, 244

L

LEO satellite systems, 4, 10, 54, 68, 71,

132, 141, 189, 192, 195

M

MAC, 18, 97, 98, 105, 110, 119, 139,

248, 256, 298

MEO satellite systems, 4, 10, 48, 71,

141

Modeling and simulation, 54

N

NCC, 17, 178, 208, 298, 327

Network layer, 243

Node-B, 139

O

OSI model, 34, 102

P

Packet scheduler, 134, 137, 140, 152,

155, 164

Performance enhancing proxies, 29, 99, 293

Power allocation and control, 50 Closed loop, 50

Feedback loop, 50 Open loop, 50 Proactive algorithms, 210

Q

QoS classes, 156, 165 QoS for multimedia services, 68 Background services, 76 Conversational services, 70 Interactive services, 73 Performance requirements, 70, 73, 74, 76

QoS based IP models, 76 Streaming services, 74 QoS mapping, 98, 256, 260

R

Radio resource management, 43, 54, 96,

101, 119, 177, 289, 303, 318 Cross-layer approach, 45, 60, 96, 99,

101, 104, 214, 295, 303, 305 Joint optimization, 95, 97–100 MAC-centric approach, 105 Dynamic allocation, 20, 47, 49, 55,

99, 101, 110, 191, 198, 208, 211,

213, 214, 218, 233, 248, 251, 256, 299

Fairness, 44, 217, 232 Reactive algorithms, 210 Receding horizon controller, 214 Resource allocation, 23, 46, 99, 121,

138, 158, 179, 184, 208, 225, 249, 299

Frequency allocation, 46 Space allocation, 46 Time allocation, 46

S

S-UMTS, 15, 58, 108, 121, 131, 152, 325 Satellite constellations/orbits, 4, 10, 275 Satellite digital multimedia

broadcasting, 325 Satellite IP networks, 31, 69, 76, 109, 248

IP QoS, 76, 109, 183, 244, 248

Proportional DiffServ, 249

Scheduling scheme, 134

Channel-aware scheduling, 135

Exponential Rule scheduler, 138

Maximum C/I scheduler, 138

Proportional Fair scheduler, 138, 147

Service level agreement, 96, 222, 246

SI-SAP, 31, 98, 256

Smith predictor controller, 214

Standardization, 322

Static algorithms, 209

T

TCP over satellite, 290

Cross-layer interactions, 294, 298

MODCOD optimization, 294 TDMA, 13

Transport layer, 99, 289 Congestion control, 291 TCP, 99, 273, 290, 294, 298 UDP, 273, 290, 305

U

UMTS, 15, 58, 121

V

VLANs for LEO constellations, 270 Voice over IP, 50, 70, 262

W

W-CDMA, 16, 46, 137