25. WiMAX LTE
, IEEE 802.16 WiMAX (World Interoperability for Microwave Access, ). : 802.16-2004 ( ) 802.16e - 2005 ( ).
WiMAX:
, , WiMAX;
Wi-Fi , , . WiMAX .
WiMAX Wi-Fi 802.11,n ( 24) MIMO, / /.
Wi
. FDD (Frequency Division Duplex), TDD (Time Division Duplex) ( ).
, , . , . , . WiM OFDM, .
OFDM
OFDM (orthogonal frequency division multiplexing) - ( 1-2 ) fc. , N n N/n , , . , , . , OFDM- T, OFDM- Ts= T+ T, T OFDM-. OFDM : N . , , , .
200 - 8 . 192 16 12 . , - OFDMA, .
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OFDM SOFDM
OFDM (Orthogonal Frequency Division Multiple Access) OFDM . , OFDM 16 . ( 1 ). OFDM , OFDM 2048. . , , , . OFDMA, , OFDMA (SOFDMA). SOFDMA : 2048, 1024, 512 128. WiMAX 1024 512 , 10 5 . 256 , OFDMA OFDM.
. 25.1 OFDM OFDMA.
. 25.1. OFDM OFDMA
, , .
, . ( 1) 1 0, . , . OFDM OFDMA . 2 . , OFDM - . OFDMA . 3 , . OFDM OFDMA . 4 QAM-16, QAM-64, QPSK, BPSK. OFDM . OFDMA QAM-16 QPSK ½ ¾. QAM-64 . WiMAX , .. . WiMAX OFDM, . MAC-. WiMAX MCS (Modulation and Coding Scheme).
MAC- WiM
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MAC- WiM : CS (Convergence Sublayer), CPS (Common Part Sublayer) (Security Sublayer). CS (IP, Ethernet .) WiM.
CPS :
;
;
.
, , .
. , . SA, PKI, [96].
SA , . SA (16 ), (Traffic encryption keys), , . , . 30 7 . 64 . : ( ), ( ) ( , ). . - , .
PKI WiMAX . 802.16-2004 ( ) , 802.16e-2005 ( ) . RSA . WiMAX -TLS RADIUS ( 24) . . AES.
WiMAX AES . , AES (. 25.2). . 2 . . 2 . .
. 25.2. WiMAX
C LTE
LTE ( , Long Term Evolution) . (4G) LTE, WiMAX. 2014 225 . LTE .
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GSM-UMTS-LTE , , ETSI, . (Realiease).
Release 7 UMTS 3GPP LTE. 3G LTE :
;
;
, 350 /.
;
IMS (IP Multimedia Subsystem). LTE , R8. 2014 R12 [5]. LTE. , R12 LTE TETRA.
LTE : OFDM, MIMO [6].
OFDM, Wi-Fi WiMAX, . MIMO LTE . ( ). ( , ).
LTE LTE Advanced. , LTE Advanced:
- 1 /, - 500 /;
- 30 /\, 15/\ ( , LTE);
LTE 3GPP (GERAN/UMTS). C GERAN (GSM/EDGE Radio Access Network) , UMTS.
. 25.3. () LTE [7].
LTE E-UTRAN (Evolved UTRAN) EPC (Evolved Packet Core), SAE ( , System Architecture Evolution). SAE EPS (Evolved Packet System). EPS MME (Moblity Management Entity) UPE (User Plane Entity). MME UE : , , . MME MME, , ( MME) , , UE, , . UPE SAE ( VLR GSM).
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E-UTRAN eNB (evolved Node B), UMTS, RNC UMTS. eNB .
. 25.3. LTE
MME (paging) . UPE . LTE , QoS. LTE . LTE. LTE IP (IMS, IP Multimedia Subsystem), . IMS . . 25.4 IMS, [8].
. 25.4. IMS
1. (Access/Transport Layer). IMS ( . LTE, UMTS, , GSM, ). , IMS . . NASS (network attachment subsystem) 3GPP , IP-, .
2. (Session Control Layer). CSCF (Call/Session Control Function) HSS (Home Subscriber Server). SCCF IMS, SIP, IP.
IMS. CSCF (Call Session Control Function): ) Proxy CSCF (P- CSCF), Intorrogating CSCF (I- CSCF), Serving CSCF (S- CSCF). P-CSCF ( IMSI, IMS, .). SIP P- CSCF I- CSCF, IMS S-CSCF, .
I- CSCF HSS S-CSCF. HSS IMS. SIP , IMS. P- CSCF I- CSCF - SIP. I- CSCF S-CSCF, SIP,
25.4.1. LTE
LTE AKA (Authentication and Key Agreement). . 25.5 LTE , [9].
. 25.5. LTE eNB Enb!!!!!!!!!!!!!!!!!
LTE , , , . HSS . S-GW (Servng Gateway) P-GW (Packet Gaeway). S-GW , eNB, LTE 2G/3G. P-GW . eNB 3G, S-GW MME. eNB UE.
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UE eNB RRC (Radio Resource Control) MME NAS (Non-Access Stratum).
. 25.6 AKA [10,11].
. 25.6.
1 2 , AKA. UMTS UE GUTI. UMTS (.. TMSI P-TMSI) MME UE MME. AKA MME UE. CK IK , UMTS.
CK=f3(K, RAND) (1)
IK=f4(K, RAND) (2)
UMTS KASME .
KASME = KDF(SNin, SQN XOR AK || CK||IK) (3)
SNin SN
KDF (Key derivation Functon) .
SQN (Sequence Number) - ;
AK (Anonymity Key) - , SQN.
SQN XOR AK MME UE ( KASME ). AKA. KASME KNASenc NAS MME UE KNASint . KASME KeNB. KeNB UE-eNB: KRRCenc, KRRCint, KUPenc.
UE-eNB RRC (Radio Resource Control). KRRCenc KeNB . KRRCint KeNB . RRC LTE UMTS. [6]. KASME KNASenc NAS MME UE KNASint .
KUPenc UE-eNB. . .
1 (. 25.6) UE MME . EPS IMSI c , , UMTS. IMSI UE MME . EPS GUTI (Globally Unic Temporary UE Identity). GUTI 3G (.. TMSI P-TMSI) MME (GUMMEI) UE MME (M-TMSI). 2 MME UE GUTI. 2 IMSI.
3 MME HSS . AV (Authentication Vector).
EPS (AV: RAND, XRES, KASME, AUTN) :
RAND ();
, XRES;
KASME;
() AUTN (An Authentication Token).
, EPS UMTS, : RAND, XRES, CK, IK, AUTN. EPS KASME, .
4.1.
4 ( ) HSS AV MME .
MME AV AV RAND AUTN.
5 MME UE. UE AUTN , RAND , () RES . RES .
6 ( ) UE RES RAND. MME RES XRES. RES XRES .
, LTE , UMTS, - ( , ).
. 25.7 HSS. HSS - (), MME IMSI SNID.
. 25.7.
K f1, f2, f3, f4, f5. f1 f5 , f2 . f3 f4 KASME 1-3 . . 5 :
SQN (Sequence Number) - ;
AK (Anonymity Key) -, SQN;
AMF (Authentication Management Field) - . AMF ;
MAC (Message Authentication Code) - () [6,12](. , .2).
MAC = f(K, AMF, SQN, RAND).
AV, AUTN, XRES ( f2) 3 KASME CK ( f3) IK ( f4). AUTN =SQN XOR AK || AMF|| MAC.