The use of Wi-Fi technology in carrier networks is the result of developments coordinated by the IEEE, WFA and WBA standardization bodies. For its part, the 3GPP standardization body has been working to integrate Wi-Fi technology into the 4G mobile network.
The first part of this book presents the characteristics of the Wi-Fi radio interface. The different IEEE 802.11b / g / n / ac physical layers characterize the implementation in the 2.4 GHz ISM frequency bands and U- NII at 5 GHz. The MAC layer defines a number of media access procedures such as scanning, associating, or transferring data.
The second part of this book deals with the architecture of the 4G network based on the Wi-Fi interface. This architecture defines several models corresponding, on the one hand, to Wi-Fi access controlled or not, On the other hand, to a handover controlled by the network or by the mobile. The integration of Wi-Fi technology resulted in a redefinition of attachment and session set-up procedures.
Smartphones have the ability to activate simultaneously the two radio interfaces, LTE and Wi-Fi, which allows to direct certain services to one and / or the other of the interfaces. The ANDSF and HotSpot 2.0 functions provide the mobile with rules for network selection and traffic control to determine which traffic is to be routed to what type of interface.
Table of Contents
List of Abbreviations xi
Introduction xxiii
Chapter 1 Architecture Based on Wi-Fi Access 1
1.1 Functional architecture 1
1.1.1 Architecture based on the S2a interface 1
1.1.2 Architecture based on the S2b interface 4
1.1.3 Architecture based on the S2c interface 7
1.2 Tunnel establishment 8
1.2.1 Architecture based on the S2a interface 8
1.2.2 Architecture based on the S2b interface 12
1.2.3 Architecture based on the S2c interface 13
1.3 DIAMETER protocol 14
1.3.1 AAA server interfaces 15
1.3.2 PCRF interfaces 20
Chapter 2 MAC Layer 23
2.1 Frame structure 23
2.1.1 Frame header 23
2.1.2 Structure of control frames 25
2.1.3 Structure of management frames 26
2.2 Procedures 30
2.2.1 Timers 30
2.2.2 Mobile registration 30
2.2.3 Data transfer 32
2.2.4 Clear channel assessment 34
2.2.5 Frame fragmentation 36
2.2.6 Standby management 36
2.3 Security 38
2.3.1 Security mechanism 38
2.3.2 Security policies 39
2.3.3 MAC header extension 39
2.4 Quality of service 46
2.4.1 EDCA mechanism 46
2.4.2 Impact on the MAC header 48
Chapter 3 802.11a/g Interfaces 49
3.1 802.11a interface 49
3.1.1 PLCP sub-layer 49
3.1.2 PMD sub-layer 51
3.2 802.11g interface 58
3.2.1 PLCP sub-layer 58
3.2.2 PMD sub-layer 61
Chapter 4 802.11n Interface 63
4.1 MAC layer evolution 63
4.1.1 Management frames 64
4.1.2 Structure of the MAC header 66
4.1.3 Frame aggregation 68
4.1.4 Control frames 70
4.2 PLCP sub-layer 72
4.3 PMD sub-layer 75
4.3.1 Transmission chain 75
4.3.2 Frequency plan 78
4.3.3 Frequency multiplexing 78
4.3.4 Space multiplexing 79
4.3.5 Modulation and coding scheme 81
Chapter 5 802.11ac Interface 85
5.1 MAC layer 85
5.1.1 Management frame evolution 85
5.1.2 Control frames 89
5.1.3 MAC header structure 90
5.2 PLCP sub-layer 92
5.3 PMD sub-layer 94
5.3.1 Transmission chain 94
5.3.2 Frequency plan 99
5.3.3 Frequency multiplexing 100
5.3.4 Spatial multiplexing 101
5.3.5 Modulation and coding scheme 102
Chapter 6 Mutual Authentication 105
6.1 802.1x mechanism 105
6.1.1 EAPOL protocol 107
6.1.2 EAP 109
6.1.3 RADIUS messages 111
6.1.4 Authentication procedure 112
6.2 Key management 114
6.2.1 Key hierarchy 114
6.2.2 Four-way handshake procedure 115
6.2.3 Group Key Handshake procedure 116
6.3 Application to the 4G mobile network 117
6.3.1 EAP-AKA method 117
6.3.2 Mutual authentication procedure 118
6.3.3 Procedure for rapid renewal of authentication 121
6.3.4 Application to the MIPv4 FA mechanism 122
Chapter 7 SWu Tunnel Establishment 125
7.1 IPSec mechanism 125
7.1.1 Header extensions 127
7.1.2 IKEv2 protocol 131
7.1.3 Procedure 137
7.2 Application to the 4G mobile network 142
7.2.1 SWu tunnel establishment procedure 142
7.2.2 Procedure for rapid renewal of authentication 145
Chapter 8 S2a/S2b Tunnel Establishment 147
8.1 PMIPv6 mechanism 147
8.1.1 Mobility extension 148
8.1.2 Procedures 149
8.1.3 Application to the 4G mobile network 151
8.2 GTPv2 mechanism 155
8.2.1 Trusted Wi-Fi access 156
8.2.2 Untrusted Wi-Fi access 158
8.3 MIPv4 FA mechanism 158
8.3.1 Components of mobility 158
8.3.2 Foreign agent discovery 159
8.3.3 Registration 160
8.3.4 Procedure 160
8.3.5 Application to the 4G mobile network 162
Chapter 9 S2c Tunnel Establishment 165
9.1 MIPv6 mechanism 165
9.1.1 IPv6 header extensions 166
9.1.2 ICMPv6 messages 169
9.1.3 Procedures 171
9.2 DSMIPv6 mechanism 177
9.3 Application to the 4G mobile network 178
9.3.1 Trusted Wi-Fi access 178
9.3.2 Untrusted Wi-Fi access 179
9.3.3 IFOM function 180
Chapter 10 Network Discovery and Selection 183
10.1 Mechanisms defined by 3GPP organization 183
10.1.1 ANDSF function 183
10.1.2 RAN assistance 191
10.2 Mechanisms defined by IEEE and WFA organizations 192
10.2.1 Information elements provided by the beacon 194
10.2.2 Information elements provided by the ANQP server 195
Chapter 11 Carrier Aggregation 201
11.1 Functional architecture 201
11.2 Protocol architecture 202
11.2.1 LWA 202
11.2.2 LWIP aggregation 205
11.2.3 LAA aggregation 207
11.3 Procedures 207
11.3.1 LWA 207
11.3.2 LWIP aggregation 211
11.3.3 LAA aggregation 212
11.4 PDCP 214
Chapter 12 MPTCP Aggregation 217
12.1 Functional architecture 217
12.2 TCP 218
12.2.1 TCP header 218
12.2.2 Opening and closing a connection 220
12.2.3 Data transfer 221
12.2.4 Slow Start and Congestion Avoidance mechanisms 221
12.2.5 Fast Retransmit and Fast Recovery mechanisms 222
12.2.6 ECN mechanism 224
12.3 MPTCP 226
12.3.1 Establishment of MPTCP connection 227
12.3.2 Adding a TCP connection 227
12.3.3 Data transfer 229
12.3.4 Closing an MPTCP connection 231
12.3.5 Adding and removing an address 233
12.3.6 Return to the TCP connection 234
Bibliography 235
Index 239
