QoS /QoE in the context of videoconferencing services over LTE/4G networks.

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1 QoS /QoE in the context of videoconferencing services over LTE/4G networks. NDIAYE Maty PhD student within France Telecom / Orange Labs ETSI workshop on telecommunications quality matters 28/11/2012, Vienna (Austria)

2 Agenda part 1 part 2 part 3 part 4 part 5 part 6 part 7 Scope of the current study conferencing services and associated codecs LTE/4G in a nutshell Goal of the experiment Description of the experimentation IP results Summary and next step 2

Scope of the current study With the important technology advances in the area of mobile devices, the development of data traffic on current 3G mobile networks is rocketing : Emergence of voice and

3 Scope of the current study With the important technology advances in the area of mobile devices, the development of data traffic on current 3G mobile networks is rocketing : Emergence of voice and video services, in particular video conferencing for personal and professional use over mobile devices The growth of consumer demands for multimedia services generates huge amount of video traffic on mobile networks This increase of mobile data consumption pushes operators to invest in new mobile broadband networks relying on advanced radio and IP network technologies 3GPP has then defined a new standard LTE/4G [Release 8] integrating several quality levels to cope with these new applications and services 3

4 calling services and associated codecs With LTE, more bandwidth and less latency for streaming multimedia contents some applications are very sensitive to network/radio conditions. there is a need to check that conversational services will perform efficiently with this new mobile network. 4 To ensure the best Quality of Experience (QoE) when dealing with mobile video calls - Selection of video and audio codecs in line with the capabilities of bearers - The user expectations (low-cost, regular, premium services) - Tradeoff between the right bitrate and the highest video and audio quality. No specific media codecs are defined for these types of services over LTE : Some recommendations propose to use the existing codecs (AMR, AMR-WB (voice) and H.263, H.264 (video) However, active works are ongoing to develop High-Efficiency Coding (HEVC) (video) and Enhanced Voice Service (EVS)(voice and audio).

5 LTE/4G in a nutshell Two main components: Evolved Packet Core (EPC) and e-utran. Throughput expected around 100 Mbps in DL and 50 Mbps in UL Reduced latency complying with the expectations of real-time applications QoS management through bearers set-up. New radio technologies : OFDMA, SC-FDMA and MIMO. All IP architecture, relying on IMS system handling SIP protocol. Figure 1 : LTE Architecture (cisco.com) Figure 2 : Qos managment 5

6 Goal of the experimentation What? : The main target is to study the usability of existing standardized codecs when dealing with videoconferencing services over currently deployed LTE/4G networks. Where? : Experiments were launched with the use of available LTE dongles and on the ImaginLab 4G/LTE experimental platform deployed in Brest (France) by Images and Networks French Cluster. ( How? : Connections were set-up using best effort mode (non-guaranteed QoS), without mobility in the present case, close to the antenna (approximately between m), within a building, using 2,6 GHz radio frequency. 6

7 LTE cartography (source : Images and Networks French Cluster) 7

Technical description of the experimentation Experimentation tools used : Orange Labs internally developed probe called

- Several codecs are implemented when setting-up end-to-end calls over the LTE network with several configurations (e.g. H264 / G722.

contents (image resolution, frame per second, bitrate, etc ) - Several key performance metrics can be gathered at the end of

8 Technical description of the experimentation Experimentation tools used : Orange Labs internally developed probe called SondeQoS : - The tool is able to set-up and tear-down videocall using the SIP protocol. - Several codecs are implemented when setting-up end-to-end calls over the LTE network with several configurations (e.g. H264 / G722.2 or H263 / G711) - Different reference audio and video files can be injected within the tool so as to stream different contents (image resolution, frame per second, bitrate, etc ) - Several key performance metrics can be gathered at the end of each call and the outcoming audio and video files can be stored for quality inspection CIF( 320x288) resoulution 4CIF( 704x576) resoulution 720p( 1080x720) resoulution 8

9 Description of the experimentation: simulation of endto-end calls over the LTE/4G via SondeQoS probe QoS & QoE over LTE/4G 9

10 Interpretation of IP results Parameters Configuration H.263/G.711 H.263/AMR-NB H.263/G.722 H.263/G H.263/AMR-WB Call registration 04.79ms 05.44ms 04.41ms 05.30ms 05.87ms Call establishment ms ms ms ms ms Throughput (average) UL = kbps DL =85.60 kbps UL = kbps DL = kbps UL = 8.98 kbps DL = 7.80 kbps UL= kbps DL = kbps UL = kbps DL = kbps UL= kbps DL = kbps UL = kbps DL = kbps UL= kbps DL = kbps UL = 9.91 kbps DL = 9.42 kbps UL = kbps DL = kbps MOS=[ ] Call registration =[04.41ms 05.87ms] Call establishment=[02.189ms ms] Percentage of audio lost packets= [0% 0.07%] Percentage of video lost packets= [0% 0.15%] Jitter=[0ms 1.27ms] MOS UL & DL = 4.36 UL & DL 4.41 UL = 4.18 DL = 4.23 UL = 4.40 DL = 4.35 UL = 4.37 DL = 4.42 H.263 profile= Baseline profile Max picture rate= 625 picture s /sec Jitter (average) Percentage of lost packets UL = 0.01 ms DL = 0.44 ms UL =0.16 ms DL= 0.05 ms UL = 0.03% DL = 0.02% UL = 0.02% DL = 0.01% UL = 0.21 ms DL = 0.95 ms UL =0.17 ms DL= 0.26 ms UL = 0.03% DL = 0% UL = 0.15% DL =0% UL = 0.01 ms DL = 0 ms UL =0.15 ms DL= 0.11 ms UL = 0.06% DL = 0% UL = 0.07% DL =0% UL = 1.20 ms DL = 1.14 ms UL =0.16 ms DL= 0.03 ms UL = 0% DL = 0.03% UL = 0% DL =0.04% UL = 1.27 ms DL = 0.75 ms UL =0.17 ms DL= 0.05 ms UL = 0.07% DL = 0% UL = 0.02% DL =0% Codec flow: G.711 = 64 kbps AMR-NB = variable rate & Voice activity detection(vad)= on (1) G.722 = 64 kbps G722.1 = 2*32 kbps stereo AMR-WB = kbps & VAD =1 10

11 Interpretation of IP results Configuration Parameters H.264/G.711 H.264/AMR-NB H.264/G.722 H.264/G H.264/AMR-WB Call registration 05.06ms 05.04ms 04.16ms 06.16ms 04.91ms Call establishment ms ms ms ms ms Throughput (average) UL = 83.88kbps DL =85.60Kbps UL = kbps DL = kbps UL = 8.28kbps DL =7.80 kbps UL= kbps DL = Kbps UL = 82.17kbps DL = 85.60Kbps UL= kbps DL = Kbps UL = 85.60kbps DL = 85.60kbps UL= kbps DL = kbps UL = 33.01kbps DL = 9.42kbps UL = kbps DL = kbps MOS=[ ] Call registration =[04.16ms 06.16ms] Call establishment=[02.171ms ms] Percentage of audio lost packets= [0% 0.03%] Percentage of video lost packets= [0% 0.08%] Jitter=[0ms 1.35ms] MOS Jitter (average) UL = 4.36 DL = 4.33 UL = 0.01ms DL = 0.94ms UL = 4.42 DL = 4.42 UL = 0.09ms DL = 0ms UL =4.24 DL = 4.22 UL = 0.02ms DL = 0 ms UL = 4.40 DL = 4.35 UL = 1.20ms DL = 1.14ms UL =4.42 DL = 4.42 UL =1.35 ms DL = 0.63ms H.264 profile= Baseline profile Level= level 2 Max picture rate= 625 pictures /sec UL =0.02ms DL= 0.04ms UL =0.03ms DL= 0.01ms UL =0.02ms DL= 0.03ms UL =0.16ms DL= 0.03ms UL =0.07ms DL=0.01ms Percentage of lost packets 11 UL =0.03 % DL = 0 % UL = 0.07% DL = 0% UL =0 % DL = 0% UL = 0.07% DL =0.04% UL = 0.02% DL = 0% UL =0.08 % DL =0% UL = 0% DL = 0 % UL =0 % DL =0.04% UL = 0% DL = 0% UL = 0% DL =0.04% Codec flow: G.711 = 64 kbps AMR-NB = variable rate & Voice activity detection(vad)= on (1) G.722 = 64 kbps G722.1 = 2.32 kbps stereo AMR-WB = kbps & VAD =1

12 Encountered difficulties Difficulty when connecting the LTE/4G dongle to a Linux environment: The Operating System Ubuntu seems the most flexible when dealing with these devices Resolved thanks to AT commands (3GPP TS V ( )). Non-conformity of the specification implementation. SIP Register messages have to be customized so as to register with the IMS call manager Interoperability issues of the firmware version with the LTE/4G architecture In some cases, the dongle firmware has to be upgraded or downgraded to work correctly with the underlying LTE platform The current underlying system was not able to manage differenciated QoS The tests were run so far within a building, which show that 2,6 GHz Frequencies are not well-suited for in-door tries The LTE connection is asymmetrical so that the QoS on the UL and DL may be very different 12

13 Summary A first experiment of videocalling on experimental LTE network These trials were performed using a true IMS infrastructure (Session Border Controller, IMS Call Server, end-to-end delays, real-life variable radio conditions) Several LTE dongles from different vendors were tested over Linux and Windows An internally developped tool was made ready for operational measurements This set of tests give a better knowledge about metrics to calculate (call establishment time, registration time, bandwidth, loss, jitter) Different resolutions of images and audio and video coding schemes were used The asymmetrical behaviour of the LTE connection is an issue that may have impact of the choice of codec. The 2,6GHz Frequencies are not well-suited for in-door tries 13

14 Next steps Integrate outdoor mobility, distance to cell in real-live network QoS management ( PCRF to be included) with the addition of different configuration parameters (such as QCI, ARP or DSCP) Tests under variable radio conditions (network disturbance tools) Integration of new codecs (such as OPUS or HEVC (2013)) Subjective testing 14

15 Thanks

Spirent Landslide VoLTE

Spirent Landslide VoLTE /IMS Node and SIP UE Emulation Voice over LTE () is the combination of IMS-based voice, messaging and video services over the 4G mobile network. To ensure a successful transition, mobile carriers and equipment