A Unified Service Platform: ZXUP10

The ZXUP10 system can provide a unified solution for different networks and implement IN services for Softswitch, PSTN, GSM, PCS and CDMA networks.

It is very flexible in networking due to its open service platform using Parlay/OSA and powerful protocol processing capability.

It enables telecom operators to strengthen the management of service providers, introduce competitive mechanisms, make maximum profits, and increase their ARPU.

1 Development Trend of  Intelligent Services
Services on traditional Intelligent Networks(IN) are created by Service Creation Environment Point (SCEP), and uploaded online to Service Control Point (SCP) to run via Service Management Access Point (SMAP) and Service Management Point (SMP). INs available can meet most demands of value-added voice services. But IN is not a completely open network. It is very difficult to create services on it by SCEP.

  Due to the fact that SCEP has not been defined with a unified service file format yet, unified service models are generally provided by SCP equipment providers, not by operators or independent software developers. This brings about some weaknesses: services do not always meet end user´s requirements; equipment providers may not respond in time when services need to be created or modified; it cannot match the trend of separating calling from the bearer.

  Traditional IN and its bearer network are combined closely. Without unification of different protocols, IN services on PSTN, GSM, CDMA and PCS networks are different from each other, impeding convergence of the fixed network, mobile network and data network.

  The new generation service platform adopts an open service architecture (OSA) that uses Parlay Application Program Interface (API) to open capabilities of the bearer network to the third party. With such an architecture, an operator is only responsible for construction and maintenance of the bearer network, while a third party such as an independent software developer provides application servers.

  Since API has abstracted the network capability, application server providers only need to know contents of API, with no necessity to understand the complicated protocols of the bottom network entity in detail. It is accordingly possible for application server providers to focus on creating services and meeting user´s needs.

  Bottom network entities are converged at Parlay Gateway. The gateway also "shields" the bottom network from the upper level applications. Therefore, it is entirely possible to realize the convergence of voice, data and multimedia services on the new generation service platform. Meanwhile, the new platform shares the traditional protocols of existing networks (such as INAP and CAP), so it can accept all services on PSTN. It is also compatible with the current intelligent network.

  A unified service development platform is just like an expressway for an operator. Service developers provide various "cars". Users can freely choose a "car" to get on. The operators make profits by charging users for the use of "expressway", but they should provide the technical management of the "car". Therefore, a multi-win result is obtained.

  Operators focus on the improvement of network utilization and network maintenance, and make profits together with service providers. Then more independent service providers can enter the telecom market, thus bring abundant services, shortened service creation periods and healthy competition environment. With so many service providers and diversified services, end users finally have more service options.

2 ZXUP10 System Architecture
The ZXUP10 system, a unified service platform developed by ZTE, adopts the Parlay/OSA architecture. It can be divided into three functional layers.
  (1) Application Layer
Parlay API is used to create various applications and achieve specific service logics at this layer.
  (2) Service Capability Layer
At this layer, Parlay API abstracts and encapsulates capabilities of the bottom network to achieve service capabilities that Parlay API defines, and allows the third party to use API.
  (3) Adaptation Layer
The layer is the protocol interface layer of the service capability server and the bottom network resources. All network protocols are converged and translated there.

  At the application layer, via Parlay interface, various requests are sent to the service control module. The module then uses a unified interface to transmit the request to corresponding adaptation layer where the conversion of protocol parameters is completed. In the end, the request is sent to the network resource layer. Conversely, messages at the resource layer are transmitted to the service control layer via the adaptation layer, and finally reach corresponding interfaces at the application layer by callback. In this way, the interaction between the application layer and the bottom network is realized.

  ZXUP10 can provide a powerful protocol adaptation function. It can support the following protocols:

• Service application protocols, including Parlay, INAP (CS2), CAMEL2/CAMEL3, MAP, WIN and RADIUS
• Transmission control protocols, including TCP, UDP, SCTP, TCAP/SCCP and M3UA
• Media control protocols, including H.248, SIP and MGCP
• Other protocols, including IMAP/SMTP, SMPP, CMPP and LDAP

  It can provide a unified solution for different networks and implement IN services for Softswitch, PSTN, GSM, PCS and CDMA networks. It provides interfaces with the short massage center, home location register (HLR), AAA server, mail server and billing center, and supports value-added services of voice, data, messaging and positioning. It also has functions such as multiparty call, conferencing, short message notification, mail notification, call notification and fax.

3 Networking Plans of  ZXUP10
The ZXUP10 system is very flexible in networking due to its open service platform using Parlay/OSA and powerful protocol processing capability. As shown in Figure 1, it can simultaneously provide IN services for multiple networks.

  It also supports multiple networking modes on a Softswitch network.
  (1) Networking with Traditional Protocols
Softswitch is used as traditional Service Switching Point (SSP), and the Intelligent Network Application Protocol (INAP) is used as the access protocol. The networking plan can be made as shown in Figure 2.

  (2)Network with SMDS Interface Protocol (SIP)
Softswitch is used as the trigger point, and SIP as the access protocol.
  (3) Networking with INAP/SIGTRAN Protocol
The existing service switching point is used as the trigger point. ZXUP10 platform connects the signaling gateway by using SS7 SIGTRAN Protocol. As shown in Figure 3, such a networking plan can meet the intelligentization requirement of the whole network.

4 Service Advantages of  ZXUP10
ZTE´s unified service platform completely supports traditional IN services such as the Deposit Card, Campus card, VPN, reverse charge call, number portability, ONLY (One Number Links You), private network card, universal call and coloring ring. On a Softswitch network, the platform can also provide web-based IN services, such as the web call, click dialing, click fax, web conference, universal messaging, ONLY and Overall Digital Assistant (ODA). These services have been launched on Softswitch test networks of China Unicom Shenzhen Branch and China Netcom Chongqing Branch.

  The ZXUP10 system has the following advantages:
  (1) The platform provides standard and opened interfaces for the third party, so the service providers, as a third party manufacturer, can be introduced to the industrial value chain, which brings a revolution of service provision.
  (2) Parlay protocols can provide a rich set of capabilities. Therefore, special service requirements such as multi-party calling, telephone conference, recording and faxing can be easily realized. The capability set covers the Circuit Switched Domain  and Packet Switched Domain and corresponds well to capabilities defined by CS2 and CAMEL3 Protocols of INAP. Besides, Parlay is a set of open protocols, which can be enriched and perfected.
  (3) ZXUP10 supports multiple protocols including INAP, CAMEL, WIN, SIP, MGCP and SMPP. It shields the bottom bearer network, and provides flexible networking modes. It can keep the original access mode unchanged to save the network construction cost, which especially benefits the deployment of integrated VPN services.
  (4) With additional functions for various services, the platform can make operators to get more benefits from the initial investment.
  (5) The platform provides a flexible billing function, supporting billing by time, traffic flow, contents and quality of service. It can also provide diversified billing sets to meet the requirements of different operators.
  (6) Applications can be carried on different application servers to reduce system faults. When a service failure or overload occurs, other services won´t be affected, which can effectively enhance system stability.
  (7) The system architecture enables operators to strengthen the management of service providers,  introduce competitive mechanisms, make maximum profits, and increase ARPU.

References
[1] Ministry of Information Industry of PRC. Technical Requirements of Application Server Interface Based on Softswitch [Z].
[2] ETSI. Parlay 3.1 Specifications [EB/OL].
http://docbox.etsi.org/TISPAN/Open/OSA/Parlay31.html.

Manuscript received: 2004-01-30