Wi-Fi Integration to the 4G Mobile Network

The adoption of smartphones has had as a corollary the use of services that require streaming, such as video streaming, which is a constraint for the 4G mobile network. The integration of the network of Wi-Fi hotspots deployed by the operators adds capacity to the 4G mobile network. 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