C4 higa@comm.eng.osaka-u.ac.jp 1 IP 1.1 1. IP IP 2. 1.2 1.2.1 IP IP (Internet Protocol telephone) IP VoIP(Voice over Internet Protocol) IP IP (Network Access Control) IP IP (Call Control) (Terminal Control) (streaming) IP H.323 SIP(Session Initiation Protocol: ) H.323 IP SIP IP H.323 H.323, HTTP FTP 2 IP 1
SIP SDP(Session Description Protocol) RTSP(Real-time Streaming Protocol) RTP(Real-time Transport Protocol) IP 1 [1] 1: IP RTP(Real-Time RFC1889 Transfer Protocol) SDP(Session RFC2327 Description Protocol) SIP(Session RFC3261 Initiation Protocol) H.323 ITU-T H.323 1.2.2 SIP SIP UA(User Agent: ) UAC(User Agent Client) UAS(User Agent Server) IP (Proxy server) (Redirect server) UA (Register server) UA (Location server) UA UA 1.2.3 SIP SIP SIP (SIP message) SIP UAC UAS 6 2 SIP [2] INVITE IP BYE ACK INVITE OPTIONS CANCEL 2
INVITE ACK CANCEL BYE OPTIONS REGISTER INFO 2: SIP UAC UAS INVITE REGISTER 3 [2] 3: SIP 100 Trying (Provisional) 180 Ringing 200 OK (Final) 301 Moved permanently 400 Bad Request 401 Unauthorized 5** Server Failer 600 Busy Everywhere 604 Does Not Exist Anywhere 606 Not Acceptable 1.2.4 SIP 1 SIP UAC INVITE SIP SIP UAS INVITE UAS SIP 180 Ringing SIP UAC UAS 200 OK SIP UAC UAC SIP ACK UAS UAS 3
BYE SIP 200OK 1: SIP 1.2.5 MOS MOS(Mean Opinion Score: ) MOS (Absolute Category Rating : ACR ) ACR ( 4) ACR 4: MOS Score 5 (Exellent) 4 (Good) 3 (Fair) 2 (Poor) 1 (Bad) 4
( Listening Effort Score ) ( 5) Score 5: 5 (Complete relaxation possible; no effort required) 4 (Attention necessary; no appreciable effort required) 3 (Moderate effort required) 2 (Considerable effort required) 1 (No meaning understood with any feasible effort) 1.2.6 PSQM PESQ R PQSM ( Perceptual Speech Quality Measurement : ) ITU-T P.861 PSQM 2001 P.862 PESQ ( Perceptual Evaluation of Speech Quality ) IP 2: PSMQ 1.3 1.3.1 (4 ) LAN (1 ) PHS CS(1 ) (1 ) PC(2 ) (1 ) 5
3 () 3: 1.4 1.4.1 1. 3 PC 2. AP 3. LAN TCP 4. LAN TCP [bps] ( 6) 1.4.2 LAN TCP 6: LAN 6 9 12 18 24 36 48 54 Mbps BPSK BPSK QPSK QPSK 16-16- 64-64- QAM QAM QAM QAM 1/2 3/4 1/2 3/4 1/2 3/4 2/3 3/4 6
1.4.3 1. N900iL N902iL 2. PC UDP 3. MOS (10 ) 4. MOS 1.4.4 1.5 (G.711 G722 G.723.1 G.728 G.729) 2 GPS(Global positioning System) RFID(Radio Frequency Identification) 2.1 2.1.1 a(t) a(t) = A(f)e j2πft df (1) A(f) a(t) h(t) v i (t) v o (t) v o (t) = v i (t) h(t) = 7 v i (τ)h(t τ)dτ (2)
v i (t) v o (t) h(t) V i (f) V o (f) H(f) V o (f) = H(f)V i (f) (3) H(f) h(t) ( NA) NA NA B w B w 1/B w h(t) 1/B w 1/B w NA [3] 2.1.2 [4] D H D D θ D H = sin θ, (4) D D = cos ( π 2 cos θ) (5) sin θ P 0 P G G = P 0 P 2.14dB (6) 2.1.3 [4] Γ Γ = ( ) 4πD 2 10 log λ (7) =20 log 4πD λ (8) Γ λ D [db] [m] 2.4GHz 1m 40dB Γ = 40 + 20 log D (9) 8
2 3.5 Γ[dB] = ( ) 4πD 3.5 10 log λ (10) = 35 log(4πd/λ) (11) 3 4 2.1.4 [4] P r P r = P t L ft + G at Γ + G ar L fr (12) P t, L ft, G at, G ar, L fr 2.2 1. 1.9GHz SPAN B w =1GHz 2. 3. 4. 10 4 2.3 1. 2. 3. 9
4: 2.4 1. 2. 3. 4. 2.5 1. 2. 2.6 E2 222 10
[1] Henry Sinnreich, Alan B.Johonsoton, TCP/IP SIP,, 2003, pp. 13-14. [2] VoIP,, 2003, pp. 210-215. [3] S. [4] RF no.3, CQ 2008. 11