IMS Representative Application Server Dynamic Load Distribution
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Solution Overview
Problem
Existing IP-based mobile communication systems face challenges in dynamically allocating application servers to manage increasing user loads efficiently, leading to operational and maintenance costs, service disruptions, and delays due to static allocation methods and non-standard protocols.
Innovation Solution
Implementing a hierarchical structure within the IP Multimedia Subsystem (IMS) using a representative application server and multiple backend servers, where control messages are processed through the SIP protocol, allowing dynamic allocation and load distribution, reducing transmission delays and ensuring interoperability between heterogeneous servers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple application servers are installed with the same function and subscriber information is divided and registered in a predefined home subscriber server, then load distribution is achieved, but operation and maintenance costs increase since subscriber information should be periodically updated under variable operating environments
Solution Approach 1:
The patent implements dynamic allocation of application servers where the home subscriber server (HSS) maintains mapping information between subscriber identities and currently active application servers. This allows the system to adapt to variable operating environments by periodically updating server allocations based on current system state, rather than using static pre-allocation. The dynamic nature enables automatic adjustment when servers are added, removed, or experience failures, reducing manual operation and maintenance overhead.
2Ease of operation
If a specific application server is allocated to a user, then service processing is simplified, but the user can never use any service when the operation of a specific application server allocated to the user is stopped
Solution Approach 1:
The patent implements a feedback mechanism where the home subscriber server continuously maintains and updates mapping information between subscriber identities and application server statuses. When an application server becomes unavailable, the HSS detects this through failed communication attempts or status notifications and automatically updates its internal mapping table. Subsequent service requests for affected users are then redirected to alternative available servers, ensuring continuous service availability while maintaining simple processing logic at the application server level.
3Adaptability or versatility
If a logical application server is configured by integrating multiple application servers through a distributor, then dynamic allocation is achieved, but re-transmission delay occurs since the request message should pass through a distributor
Solution Approach 1:
The patent implements preliminary action by having the home subscriber server pre-compute and maintain optimal application server mappings for all subscribers before service requests arrive. The HSS proactively monitors application server availability and pre-updates its mapping information based on predicted load conditions and server capacities. When service requests are received, the pre-computed mappings enable direct routing to appropriate servers without requiring real-time distribution logic, thereby eliminating re-transmission delays while maintaining dynamic allocation capabilities.
4Productivity
If a non-standard control protocol is used between application servers for load distribution, then load distribution is achieved, but it may not be applied between heterogeneous application servers
Solution Approach 1:
The patent implements universality by using the standardized SIP (Session Initiation Protocol) for all communication between application servers and the home subscriber server. The HSS acts as a universal interface that translates between different server types and the standardized protocol. This allows heterogeneous application servers from different manufacturers to interoperate seamlessly, as they all communicate through the same SIP-based interface defined by the 3GPP TS 23.228 standard, eliminating interoperability issues while maintaining efficient load distribution capabilities.
Data Source
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AI summary
A method for processing a message from a user equipment (UE) in a wireless communication system supporting a multimedia service. The method comprises the steps of receiving, by a representative application server, an invite request to create a new dialog from a serving-call session control function (S-CSCF), allocating, by the representative application serer, a specific lower-layer application server from at least one lower-layer application server to the UE, sending the invite request to the specific lower-layer application server without recording the representative application server on a record-route of the invite request, receiving, by the representative application server, a response message from the specific lower-layer application server, and sending, by the representative application server, the response message to the S-CSCF, wherein the invite request is processed by the specific lower-layer application server wherein the specific lower-layer application server is allocated based on user allocation information.