ETSI TR 103 635 V1.1.1 (2019-11)

ETSI TR 103 635 V1.1.1 (2019-11)






TECHNICAL REPORT
Digital Enhanced Cordless Telecommunications (DECT);
DECT-2020 New Radio (NR) interface;
Study on MAC and higher layers

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2 ETSI TR 103 635 V1.1.1 (2019-11)



Reference
DTR/DECT-00317
Keywords
5G, DECT, IMT-2020, interface, MIMO, OFDM,
radio
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3 ETSI TR 103 635 V1.1.1 (2019-11)
Contents
Intellectual Property Rights . 9
Foreword . 9
Modal verbs terminology . 9
Introduction . 9
1 Scope . 11
2 References . 11
2.1 Normative references . 11
2.2 Informative references . 11
3 Definition of terms, symbols and abbreviations . 13
3.1 Terms . 13
3.2 Symbols . 14
3.3 Abbreviations . 14
4 Introduction to DECT-2020 Use Cases and their Requirements . 18
4.1 Introduction . 18
4.2 Other Design Targets for DECT-2020 . 18
4.3 IMT-2020 scenarios and performance requirements . 18
5 Methodology, initial sources, simulation tools, models and material from the PHY layer . 19
5.1 Initial sources . 19
5.2 Simulation tools . 20
5.3 Channel models . 20
5.4 Channel measurements . 20
5.5 Review of material from the PHY layer . 20
5.5.1 "Standard" frames (long and short variants) . 20
5.5.2 Beacon frames . 21
5.5.3 RAC and ULE frames . 21
5.5.4 HE frames . 21
5.5.5 Items requiring further study . 21
6 Channel Access Concepts for DECT-2020 . 21
6.1 Review of previous design choices . 21
6.2 Possible approaches for the channel access . 22
6.2.1 General . 22
6.2.2 Concept 1: improved WLAN approach . 22
6.2.3 Concept 2: scheduled operation design with complete MAC design . 22
6.2.4 Concept 3: the best of 1 + 2 . 22
6.2.5 Decision and working assumption . 23
6.2.5.1 Working decision on overall channel access concept . 23
6.2.6 Expected spectrum bands . 23
6.2.7 Specifications for channel access and service coexistence . 23
6.3 Void . 24
6.4 Void . 24
6.5 Contribution 1: Channel access for DECT-2020 . 24
6.5.1 Background . 24
6.5.2 DECT "core band" (1 880 MHz - 1 900 MHz) . 25
6.5.3 MAC Channel Access Background . 25
6.5.4 Notes on Last Minute Scanning . 26
6.5.5 Summary of Working Assumptions . 27
6.5.6 Channel Access - Idea 1 . 27
6.5.7 Channel Access - Idea 2 . 29
6.6 Contribution 2: Channel access for DECT-2020 . 31
6.6.1 Aspects to be considered . 31
6.6.2 Proposal . 31
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4 ETSI TR 103 635 V1.1.1 (2019-11)
6.7 Contribution 3: Channel access considerations . 32
7 MAC Protocol Function and PHY Services . 33
7.1 A flexible lower MAC model for DECT-2020. 33
7.1.1 Overview . 33
7.1.2 Types of possible systems . 33
7.1.3 The model "A", an intermediate system operation model suitable for many systems and types of
traffic . 34
7.1.3.1 Design targets . 34
7.1.3.2 The design . 34
7.1.3.3 Remarks . 34
7.1.3.4 Elements taken from other MAC study areas. 34
7.1.3.5 Basic design . 35
7.1.3.6 Broadcast information . 35
7.1.3.7 The message "sequence" . 36
7.1.3.8 Configuration of scheduled services . 36
7.1.4 Slot allocation and message/response sequences . 36
7.1.4.1 Slot allocation . 36
7.1.4.2 Beacon bearers . 36
7.1.4.3 Scheduled services . 36
7.1.4.4 Random Access channels . 36
7.1.4.5 Packed mode traffic - single channel . 36
7.1.4.6 ULE channels . 37
7.1.4.7 Packet mode traffic - wideband . 37
7.1.4.8 Packet mode traffic - downlink packets - Requires further study . 38
7.1.5 Example figure . 39
7.2 Void . 39
7.3 Dual mode solution for the beacon bearer . 39
7.3.1 Summary . 39
7.3.2 Assumptions . 40
7.3.3 Proposal . 40
7.3.3.1 Idea . 40
7.3.3.2 Terminology and tentative construction . 41
7.3.3.3 Structure of the bearer . 41
7.3.3.4 Example of capacity calculation . 41
7.3.3.5 Operation of the bearer and content of the fields . 41
7.3.3.5.1 General . 41
7.3.3.5.2 MAC Information in the "A" field . 42
7.3.3.5.3 MAC Information in the "B" field . 42
7.3.3.5.4 Further ideas on beacon bearer content . 42
7.3.3.6 For further study . 43
7.4 Void . 43
7.5 Latency Considerations . 43
7.5.1 Overview . 43
7.5.2 Control Plane Latency . 43
7.5.3 User Plane Latency . 45
7.6 HARQ . 46
7.6.1 Overview . 46
7.6.1.1 Simple HARQ . 46
7.6.1.2 Hybrid ARQ with "Soft-Combining" . 46
7.6.1.3 "Stop-and-Wait" or "Selective Repeat" . 46
7.6.1.4 "Adaptive Re-transmission" vs "Non-adaptive Re-transmission" . 47
7.6.2 HARQ in DECT-2020 . 47
7.6.3 HARQ Implementation Considerations . 48
7.7 PHL Header Design. 48
7.7.1 Design Rationale . 48
7.7.2 Header Field Contents . 49
7.7.2.1 Header type/version/extension . 49
7.7.2.2 Modulation Coding Scheme (MCS) . 49
7.7.2.3 Number of Spatial Streams . 49
7.7.2.4 Channel Coding Algorithm . 49
7.7.2.5 Transmission Bandwidth . 49
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5 ETSI TR 103 635 V1.1.1 (2019-11)
7.7.2.6 Transmission Length . 50
7.7.2.7 Extras . 50
7.7.2.8 CRC. 50
7.7.3 Header Field Configurations and Size Estimates . 50
7.8 Proposal of unification of the initial part of all random access PHY layer packets and additional
observations on the physical layer . 53
7.8.1 Proposal of modification to the "long format" packet format . 53
7.8.1.1 Rationale . 53
7.8.1.2 Change request to PHY layer . 53
7.8.2 New editorial conventions - position of the inter-slot guard and new A/B terminology . 54
7.8.3 Proposal of extension of the "A" symbols . 54
7.8.4 Further observations to the PHY layer . 55
7.8.4.1 General . 55
7.8.4.2 STF time is perhaps too large . 55
7.8.4.3 CTF time is perhaps too large . 55
7.8.4.4 The current design of the standard long format packets requires knowing the length of the whole
packet at the beginning . 55
7.8.4.5 The current design of the standard long format packet is probably too weak (channel tracking)
for long packets . 55
7.8.4.6 MIMO training in long format is inefficient and does not take into account the available
frequency resolution . 55
7.8.4.7 The current design of the standard short packet contains unnecessary STF and may be optimized . 56
7.9 Proposal for Modified PHL Packet Format and Channel Estimation . 56
7.9.1 Background . 56
7.9.2 Different preambles in different packet types . 56
7.9.3 Optimizing usage of CTF field . 58
7.10 Possible ARQ/HARQ strategies in DECT-2020 . 60
7.10.1 General . 60
7.10.2 Possible ARQ mechanisms . 60
7.10.2.1 General . 60
7.10.2.2 Traditional MAC ARQ . 61
7.10.2.3 Hybrid ARQ . 61
7.10.2.4 Retransmission of the content . 61
7.10.3 Elements to be taken into account in ARQ/HARQ design . 62
7.10.3.1 General . 62
7.10.3.2 The size of the basic unit for retransmission . 62
7.10.3.3 The range of MAC numbering . 62
7.10.3.4 The protection of the MAC numbering . 62
7.10.3.5 The identities of the transmitter/receiver and their protection . 62
7.10.4 A possible design approach . 63
7.10.4.1 General . 63
7.10.4.2 Solutions for scheduled traffic . 63
7.10.4.2.1 General . 63
7.10.4.2.2 Example scenario. 63
7.10.4.2.3 Discussion on the scenario . 64
7.10.4.2.4 Simple solution proposed for scheduled traffic . 64
7.10.4.3 Solutions for packet-mode traffic . 65
7.10.4.3.1 General . 65
7.10.4.3.2 Additional considerations . 65
7.10.4.3.3 Possible approaches for L-S approach . 66
7.10.4.3.4 Possible approaches for I-C-O approach . 67
8 Protocol Stack Architecture . 67
8.1 Introduction . 67
8.2 Concept 1. 68
8.2.1 Overall Protocol Stack . 68
8.2.2 Protocol Functions . 69
8.2.2.1 General . 69
8.2.2.2 Convergence layer . 69
8.2.2.3 Routing layer . 69
8.2.2.4 Link control layer . 69
8.2.2.5 MAC . 70
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6 ETSI TR 103 635 V1.1.1 (2019-11)
8.2.3 Layer 2 Protocol Details/Considerations for Mesh Operation . 70
8.2.3.1 MAC functions and PDU format . 70
8.2.3.2 Routing layer .
...