http://doi.org/10.5909/jeb.2011.16.5.738 MAC/PHY QoS a), a), a) Research of QoS Control for Standardization on Real-time Multimedia Service Using MAC/PHY Feedback Min Geon Kim a), Junoh Kim a), and Doug Young Suh a) MAC/PHY QoS(Quality of Service). MAC/PHY. RTCP(Real-time Transport Control Protocol).,. WiMAX CINR (Carrier to Interface Noise Ratio). Abstract In this paper, we study QoS(Quality of Service) control protocols and the effect using MAC/PHY parameters of client device in mobile network. We proposes the way of controling the bit-rate by estimating the channel condition of the client with measured MAC/PHY parameters which is sent from the client. With the proposed method, more accurate available bit-rate can be estimated compared to conventional protocol, RTCP(Real-time Transport Control Protocol). The accurate bit-rate estimation can decrease wasted bit-rate and transport delay. In the result of the advantages, the transported video quality can be enhanced. In this paper, we show the effects of enhancement using client s the field data measured in WiMAX. Keyword : Scalable Video Streaming, QoS, Cross Layer Design. a) Kyung Hee University : (suh@khu.ac.kr) IT (NIPA-2011-(C1090-1111-0001)) (2011 6 29 ),(1 :2011 8 30,2 :9 19 ), (2011 9 23 ). 3G, WiFi, WiMAX [1]
. IEEE 802.16 WiMAX. WiMAX [2]. WiMAX Wang [3] WiMAX / (multicast/broadcast service) (Cross- Layer Optimization, CLO). Hosein [4] WiMAX (Variable Bit Rate, VBR, Juan [5] WiMAX. WiMAX WiMAX.. [6][7]. (Real-time Transport Control Protocol, RTCP). RTCP. Kim [8][9] RTCP. 1. WiMAX CINR Fig. 1. The field data measured in WiMAX
RTCP end-to-end,.... RTCP..,. (Rotenburg), CINR, data. 1 CINR. 1 RTCP.. 2 MAC/PHY 3. 4 5.. MAC/PHY RTCP. RTCP MAC/PHY. MAC/PHY RTCP. MAC/PHY MAC/PHY. MAC/PHY., SINR(Signal to Interference Ratio), CINR (Carrier to Interference Ratio), SIR(Signal to Interference Ratio). IEEE802.16 (WiBRO WiMAX), IEEE802.11 (WiFi), 3GPP W-CDMA, 3GPP LTE MAC/PHY. MPEG MMT, Bulletin board R: 134 D: 350 L: 5 R: 100 D: 370 L: 6 R: 134 D: 410 L: 9 R: 54 D: 500 L: 1 R:bitrate D:delay L:loss rate IEEE802.16 SINR 20dB Bandwidth 5, 7, 8.75, 10MHz Buffer full : 15% BER : 10-5 H-ARQ multi ch W-CDMA SIR 19dB Bandwidth 5MHz Buffer full : 16% BER : 10-5 H-ARQ 6ch LTE Effective CINR 21dB Bandwidth 10MHz Buffer full : 19% # of users : 14 BLER : 10-2 H-ARQ WiFi SNR 16dB Bandwidth 11, 20MHz Buffer full : 26% BLER : 10-5 ARQ+option 2. QoS Fig. 2. Concept of network abstraction for QoS control
. MPEG(Moving Picture Experts Group) system MMT(MPEG Media Transport) CLD(Cross Layer Design)NAM(Network Abstraction for Media) MAC/PHY. 2. RSVP tspec RTCP QoE. MPEG DASH(Dynamic Adaptive Streaming over HTTP). RTCP QoS. MAC PHY (10ms)... NAM bulletin board MAC/PHY NAM bulletin board. 3 NAM. NAM. 1 NAM. MAC/PHY. QoS,,. RSVP(ReSourcereser Vation Protocol) 1. (NAM ) Table 1. Network Abstraction for Media (NAM Information) Field Type size (bits) channel_id unsigned integer 6 token_bucket_rate Float 32 token_bucket_size Float 32 peak_data_rate Float 32 maximum_delay Float 32 frame_size unsigned integer 32 frame_loss_ratio / lost_frame_number float / unsigned integer 32 APP NAM bulletin board MAC APP NAM bulletin board MAC P eriodic_update Period ic_upd ate Read_NAM B GetNAM B P eriodic_update Read _NAMB Period ic_up date APP NAM bulletin board MAC Read_NAM B Period ic_upda te Non- period ic inf o occur No n- Read_NAM B Periodic_up date Period ic_up date Read _NAMB periodic_up date Load_NAM B Periodic_up date Period ic_up date Period ic_upda te 3. MAC (APP) NAM a) NAM b) NAM c) NAM load Fig. 3. Flowchart of exchange information using NAM
QoS tspec. tspec RTCP. tspec RTCP MAC/PHY. tspec RTCP. - channel_id: the identifier to classify each network or session - token_bucket_rate:guaranteed average bit-rate in MAC/PHY layer represented as kilobits per second (kbps). - token_bucket_size: token bucket depth of the buffer in MAC/PHY layer represented as kilobits (kbits) - peak_data_rate: available peak bandwidth in MAC/ PHY layer - maximum_delay: maximum transport delay represented as milliseconds (ms) - frame_size: size of frame which is the transport unit in MAC/PHY represented as kilobits (kbits) - frame_loss_ratio/ lost_frame_number: frame loss rate or the numbers of frame loss calculated in MAC/PHY layer. 4.. (Base station) (channel buffer). 1), 2), 3). 1. (client) CINR (modulation and coding scheme, MCS) R[n] [8]. CINR. [8].. 4. Fig. 4. Concept of proposal system
5. CINR X[n] ( T_s = 200ms) Fig. 5. Autocorrelation of CINR X[n] (sampling period T_s = 200ms) (1) 5. 5 2 CINR 200ms.. 2. (client and base station) where Client server (CINR).. 5. feedback period T. (2). where K T Ts (2) R MCS,. T T s 200ms. 200ms. m 1 - Fixed Feedback Period(FFP): (T) - Feedback at Abrupt Change(FAC): FFP, FAC (D). D 6. 6 2 CINR (R) (R[n]- R[n-1] ). 200kbps 80%.
6. Fig. 6. PDF of difference of R[n] and R[n-1]. 3... (5). 3. (server and base station) delay E B n R n R [n]. (α, scale-down factor) R [n] (3). R [n] R[n]. B[n] (4). R n i f. R [n] (3) α. 7.. 7.... 2~3, 300ms. =0.99, =20Mbits,
7. B_max α Fig. 7. Overflow and delay according to B_max and α α=0.94, B_max=14.5Mbits.. RTCP Round Trip Time (RTT). RTCP RTT.,. 7 2.32, 0.39.. CINR SVC Soccer 4CIF SNR 7 8. RTCP Fig. 8. Prediction of Bit rate using RTCP
9. CINR Fig. 9. Prediction of Bit rate using CINR feedback. 8 RTCP. 8, 9 3.1 CINR (MCS).. CINR 9. 9 FFP T 1. 1 Fig.8.. 10. 10. CINR RTCP (con str.) Fig. 10. A comparison of the method using CINR feedback and RTCP (con:conversation, str:streaming)
10 Rwaste. Rexcess..,... (str) (con) FFP FAC, RTCP. FFP T 1,3,5, FAC D 200, 300 kbps. FFP T, FAC D. 2.3.. RTCP. 800kbps 600 kbps... 11 PSNR. FFP 1 11. ( ) Fig. 11. A comparison of video quality
. 1... 11 5 PSNR.. RTCP QoS MAC/PHY QoS. RTCP, MAC/PHY CLO.,, CLO. MPEG CLO. CLO, QoS MAC/PHY.. RTCP. PHY CINR. WiMAX PHY CINR CINR. WiMAX CINR. CINR CINR. 600~800kbps 5dB.... [1] IEEE Standard for Local and metropolitan area networks Part 16: Air Interface for Broadband Wireless Access Systems, Oct. 2004. [2] K. H. Teo, Z. Tao and J. Zhang, The mobile broadband WiMAX standard, IEEE Signal Processing Mag., Vol. 24, pp.144-148, Sep.2007. [3] J. Wang, M. Venkatachalam and Y. Fang, System Architecture and Cross-Layer Optimization of Video Broadcast over WiMAX, IEEE Journal on Selected Areas in Communications, Vol.25, pp.712-721, May.2007. [4] P. Hosein, Broadcasting VBR traffic in a WiMAX network, Vehicular Technology Conference, 2008. VTC 2008-Fall, IEEE 68th, pp.1-5, Sep.2008. [5] H. Juan, H. Huang, H. Huang and T. Chiang, Scalable Video Streaming over Mobile WiMAX, Circuits and Systems, 2007. ISCAS 2007. IEEE International Symposium on, pp.3463-3466, May.2007. [6] S. H. Hong, Y. H. Lee, J. Y. Jung and D. Y. Suh, A Cross-Layer Approach to Fair Resource Allocation for Multimedia Service in WiMAX, KSII Transactions on Internet and Information Systems, Vol. 4, pp.1006-1022, Dec.2010. [7] S. Sharangi, R. Krishnamurti and M. Hefeeda, Energy-Efficient Multicasting of Scalable Video Streams OverWiMAX Networks, IEEE Transactions on Multimedia, pp.102-115, Feb.2011. [8] H. S. Kim, H. M. Nam, J. Y. Jeong, S. H. Kim and S. J. Ko, Measurement Based Channel-Adaptive Video Streaming for Mobile
Device over Mobile WiMAX, IEEE Transactions on Consumer Electronics, Vol. 54, pp.171-178, Feb.2008. [9] H. S. Kim, E. S. Ryu and Jayant, N. Channel-Adaptive Video Transmission Using H.264 SVC Over Mobile WiMAX network, 2010 Digest of Technical Papers International Conference on Consumer Electronics, pp.441, Jan. 2010. - 2009 8 : () - 2011 8 : ( ) - : networed video, Cross Layer Optimization, DVC - 2010 2 : () - 2010 3 ~ : ( ) - : networked video, MPEG, Cross Layer Optimization - 1980 2 : () - 1986 6 : ( ) - 1990 6 : ( ) - 1990 9 ~ 1999 2 : HDTV - 1992 3 ~ : - : networked video