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8INTERNATIONAL SCIENTIFIC AND TECHNICAL CONFERENCE "DIGITAL TECHNOLOGIES: PROBLEMS AND SOLUTIONS OF PRACTICAL IMPLEMENTATION IN THE SPHERES" APRIL 27-28, 2023
ESTIMATION OF CONNECTION SETUP TIME FOR IPTV SERVICES USING THE
IMS PLATFORM 1Muradova A. A., 2Kayumov A.A.
1TUIT named after Muhammad al-Khwarizmi, PhD, associate professor, 2TUIT named after Muhammad al-Khwarizmi, 2-course master's degree https://doi.org/10.5281/zenodo.7857732
Abstract. The article presents the results of estimating the connection establishment time when providing IPTV services using the IMS platform. To estimate the connection establishment time, mathematical models have been developed for calculating basic delays in various sections of the network, taking into account the lengths of signaling messages. The results of estimating the connection establishment time and comparing the obtained results with the recommendations of the DSL forum (Digital Subscriber Line) and ITU-T are presented.
Keywords: IMS platform, IPTV services, estimation of connection, connection establishment time, video connection.
In the second stage of implementation of the NGN concept, the problems of convergence of fixed networks and cellular communication (mobile) networks were solved. IP Multimedia Subsystem (IMS) based on the IP protocol was recommended by the 3GPP (3rd Generation Partnership Project) and TISPAN (Telecommunications and Internet converged Services and Protocols for Advanced Networking) working groups as the main architecture for the convergence of these networks.
IPTV (Internet Protocol Television) service is one of the services provided in real-time in broadband multiservice communication networks based on the IMS (IP Multimedia Subsystem) multimedia platform. The IMS platform is designed to manage sessions during the provision of any multimedia services to users of fixed and mobile communication networks using IP/MPLS technologies. Estimation of the establishment time of VoIP voice connections using the IMS platform was performed in [1]. The procedure for establishing an IPTV (Internet Protocol Television) video connection using the IMS platform is reviewed in detail and the duration of the connection establishment is estimated.
There is a network architecture for providing IPTV services using the IMS platform. The IPTV network consists of the following main elements [2-4]: a home network containing a terminal device (TV receiver or computer), STB set-top box, and modem; a subscriber access network including access channel and digital subscriber line access multiplexer DSLAM (Digital Subscriber Line Access Multiplexer); traffic aggregation network consisting of switches; IP/MPLS transport network; Application servers and media servers.
Only a functional architecture is defined for the IMS subsystem, and the physical implementation of these functions is at the discretion of the particular manufacturer. The interfaces of the IMS platform are listed in Table 1, which shows the type of interface, the nodes of the distributed IMS system to which this interface is connected, its functions, and the signaling protocol used in the interface.
Table 1
Interfaces of the IMS platform
INTERNATIONAL SCIENTIFIC AND TECHNICAL CONFERENCE "DIGITAL TECHNOLOGIES: PROBLEMS AND SOLUTIONS OF PRACTICAL IMPLEMENTATION IN THE SPHERES" APRIL 27-28, 2023
Interface Node The task Protocol
Gm STB, P-CSCF The interface between STB and CSCF SIP
Mw P-CSCF, I-CSCF, S-CSCF The interface between different CSCF blocks SIP
ISc S-CSCF, I-CSCF, AS Exchange interface between CSCF and AS SIP
Cx I-CSCF, S-CSCF, HSS Exchange interface between I-CSCF, S-CSCF and HSS Diameter
Sh IPTV AS, HSS Exchange interface between IPTV AS and HSS Diameter
Ut STB, IPTV AS User management interface (customization of management) HTTP
Connection setup process. The average duration of signal message processing in the server or IMS functional block is assumed to be constant and equal to 20 ms. In the IP/MPLS network, signaling is determined by the formula based on the duration of the message transmission:
MPt = (1)
L VIP
where S£ - is the length of the /'-signal message in bits; vIP- network transmission speed is taken as 4 Mbit/sec.
Information about the length of alarm messages is presented in Table 2.
Table 2
The length of signal messages
SIP message Length (bytes) SIP message Length (bytes) Diameter message Length (bytes)
INVITE 976 ACK 676 UAR 618
100 Trying 496 BYE 556 SAR 728
183 Session Progress 956 REGISTER 856 SAA 798
PRACK 496 401 Unauthorized 726 LIR 458
200 OK 1036 SUBSCRIBE 946 LIA 728
UPDATE 496 NOTIFY 596 MAA 798
180 Ringing 496 486 Busy 496 MAR 728
The connection establishment time using the IMS framework can be calculated using the following formula:
A IMS = A I MSpr. + AIMSob + Aus, (2)
A IMSpr ,AIMSob - respectively, the duration of transmission of signal messages in the right direction (from STB) and in the opposite direction in the IP/MPLS network; Aus is the duration of signal message processing in IMS servers and functional blocks, including the duration of signal transmission between blocks.
A IMSpr. = 5AIPinvite + 4AIPprack + 4AIPupdate + AIPUR = 0,018 s.
AIMSob. = P100Trying + P183Session Progress + 8AP2000K + P100Ringing + APUA
= 0,036 s.
Aus= 5astb + 8Ap-cscf + 8As-cscf + 4Ai-cscf + ahss + 8Aiptvas + 5amcf= 0,780 S.
INTERNATIONAL SCIENTIFIC AND TECHNICAL CONFERENCE "DIGITAL TECHNOLOGIES: PROBLEMS AND SOLUTIONS OF PRACTICAL IMPLEMENTATION IN THE SPHERES" APRIL 27-28, 2023
The connection establishment time using the IMS framework was equal to AIMS = 0.834 seconds. Quality of signal reception according to QoE (Quality of Experience) [5] and the DSL Forum [6], according to the recommendations of ITU-T, the allowed time to change channels in the MPEG 2 standard should not exceed 1 second. Calculations show that when the connection is established through the IMS platform, the connection time does not exceed one second.
Estimated connection establishment time for IPTV services using the IMS platform. The signal procedure for establishing a connection from an IPTV subscriber to a server and an assessment of the connection establishment time for IPTV services using the IMS platform were made. The procedure for establishing an IPTV (Internet Protocol Television) video connection using the IMS platform was examined in detail and the duration of the connection establishment was evaluated. The average duration of signal message processing in the server or IMS functional block is assumed to be constant and equal to 20 ms. The transmission duration of signal messages in the IP/MPLS network was determined by the formula.
Conclusions
Calculated the connection establishment time using the IMS framework. As a result, the connection establishment time using the IMS infrastructure was equal to AIMS = 0.834 seconds. QoE (Quality of Experience) and signal reception quality according to the DSL forum, according to the recommendations of the ITU-T, the allowed time to change channels in the MPEG 2 standard should not exceed 1 second. Calculations show that when the connection is established through the IMS platform, the connection time does not exceed one second.
REFERENCES
1. A. Cuevas, J.I. Moreno,P. Vidales, and H. Einsiedler, "The IMS service platform: a solution for next-generation network operators to be more than bit pipes," IEEE Communications Magazine. Vol: 44 (8). ISSN: 0163-6804.
2. "Telecommunications and Internet converged Services and Protocols for Advanced Networking (TISPAN); IPTV Architecture; IPTV functions supported by the IMS subsystem," ETSI Technical Specification Draft, 2007-04, TS 182 027 V0.0.9.
3. WG2TD11-WI2048, "Proposal for IMS-based IPTV service and media control," TISPAN technical draft, ad-hoc IPTV TISPAN IPTV meeting, Madrid, 16 to 19 April 2007.
4. E. Mikoczy, D. Sivchenko, B. Xu, and J.I. Moreno, "IPTV Services over IMS: Architecture and Standardization," IEEE Communications Magazine, May 2008, pp.128-135.
5. "Quality of experience requirements for IPTV services," Recommendation ITU-T G1080, 2008, 44 p.
6. "Triple-play Services Quality of Experience (QoE) Requirements," DSL Forum, Tech. Rep., Dec. 2006, TR-126.
