Introduction to AXE System

Transcription

1 Introduction to AXE System 1 INTRODUCTION TO AXE SYSTEM This chapter is designed to provide the student with a general knowledge about the AXE architecture and the main changes between AXE 810 compared to previous AXE versions. The trends in current communications networks and how AXE has developed and meet the customer requirements are described and the main components of the new AXE 810 and the benefits of the modernization steps taken in AXE 810 are presented. Finally the different product lines in the fixed and mobile network are discussed and a short historical background of the AXE system and its future development is briefly presented EN/LZT R4A 1

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3 1 Introduction to AXE System COMMUNICATIONS TODAY COMMUNICATION APPLICATIONS The evolution of AXE so far, and its continued evolution into the 21-st century, reflects the changing needs of the information world. The communications industry is currently in a state of transition with many new developments introducing opportunities and challenges for both equipment suppliers and network operators. Deregulation of the market has resulted in the entry of new players, both network operators and service providers who are competing with the established operators. Major developments in the standardization field have resulted in increased competition between manufacturers with a resultant reduction in costs to network operators and end users. Today s communications networks, which previously only supported voice traffic, now also support data, Internet and multimedia traffic. Subscribers are demanding new services, increased mobility and higher bandwidth in the access network. Operators are linking together to form global companies providing worldwide-customized services. Subscriber mobility is now a key feature of communications. This advance has been made possible by the successful implementation of second generation mobile cellular communications systems, such as the global system for mobile communications (GSM), the digital advanced mobile phone system (D-AMPS) and the personal digital cellular (PDC). Third generation systems development will provide a worldwide mobile communications network utilizing both land and satellite technologies. AXE is a state-of-the-art communication platform comprising a powerful set of revenue-generating and cost-reducing features, a cornerstone in the realization of the emerging multi-service and 3G networks. The provision of services within communications networks has traditionally been focused on implementing service functionality in the individual nodes within the network. The first automatic communications network application was the public switched telephone network (PSTN). The integrated services digital network (ISDN) was the next major network EN/LZT R4A 3

4 AXE Survey application to be implemented. One of the main features of ISDN was the introduction of digitalization into the subscriber The public land mobile network (PLMN), wireless network, which provided mobile telephony services, pure data/ip networks, cable TV/CATV networks etc. Leased lines and private wires traditionally provided the infrastructure for business communications. The introduction of the intelligent network application has changed this focus. With an intelligent network, service intelligence is located at a central location and not in every node. The intelligent network is like an invisible layer running alongside an existing network. This layer is packed with services that can be activated and linked onto the network at any time and in any combination. These intelligent network services dramatically extend the scope of communications. This leads to a so called vertical orientation, where the operator offers everything from subscriber access to service creation and service delivery across a wholly-owned network infrastructure optimized for a particular service. Each vertically integrated network incorporates its own protocols, nodes and end-user equipment/terminals. Today Single-service networks Future Multi-service networks/client-server Services Content Servers Communcation Control Content PLMN PSTN/ISDN Data/IP Networks CATV Backbone Network Access Access Access Access Transport & Switching Networks Clients Figure 1-1 Next Generation Network Structure This orientation means that the telephony and data service networks are more or less kept separate. However, the ability of the networks to carry similar services (Voice over IP, modem 4 EN/LZT R4A

5 1 Introduction to AXE System data in PSTN) and the cost to handle many networks are drivers towards a convergence between telecom and datacom networks. The key distinguishing feature between modern network operators is the range and quality of the services they provide. The provisioning of new, advanced services can give a network operator a major competitive advantage. Intelligent networks enable the rapid creation and supply of advanced supplementary services in both fixed and cellular networks. Modern communications networks around the world require a signaling system, which allows different applications to interwork successfully and provides data communications paths between network nodes. The signaling system no.7 (SS No. 7 or SS7) standard was developed to meet these demands. SS No.7 is an advanced signaling system capable of supporting all present and future network applications. New demands on the amount of control information transmitted make it possible to provide high speed signaling connections. The converged network must fulfill requirements for all kinds of multiservice traffic. The convergence will start in the network core, which will carry all types of traffic in packets, and have the following layered ( horizontal ) structure: Connectivity backbone network - optimized for the transport and switching of large amounts of data Service and control layer - here the intelligence in the network resides for everything from call control to signaling. Content and application servers - reside outside the network itself - for instance, on the Internet The heavy bandwidth increase in data (and video) traffic towards broadband is leading to a bottleneck in narrowband access networks - whether or not they are wire line or wireless or both. Therefore new access systems appear: ADSL (Asymmetrical Digital Subscriber Line), UMTS (Universal Mobile Telephony System), Cable-TV networks for broadband Internet and others. Today a limited number of modern networks are integrated or permit unbundling; It is possible to use common fiber, synchronous digital hierarchy (SDH), and synchronous optical network (SONET) technology as a common transport network for a number of different services. EN/LZT R4A 5

6 AXE Survey Content SCP Appl Servers HLR Control Telephony Server MSC Server Connectivity Resource Node MGW Wireless Access Connectivity backbone (ATM, IP, ) MGW Wireline Access MGW MGW Internet Intranets PSTN/ISDN/ PLMN Figure 1-2 Network evolution The connectivity network constitutes a move away from vertically integrated networks to horizontal networks, in which transport and switching can be shared by numerous services. For telephony service, the International Telecommunication Union (ITU) and Internet Engineering Task Force (IETF) have drafted standards for splitting the service adapter into a controlling entity (media gateway controller, MGC) and a bearer plane adapter (media gateway, MGW), which adapts to the technology employed in the connectivity network. The media gateway controller is also referred to as a telephony server or MSC (Mobile Switching Center) server. AXE is architecture for the converging services of telecommunications, information technology (data communications and the Internet) and entertainment (the Internet, cable television and video communications). The AXE architecture is an open architecture which is capable of supporting a whole range of communication services for large or small network operators in public fixed and mobile networks. AXE is a future-proof solution based on continuous research and development in the field of communications and meets the demands of the future by incorporating advances such as increased processor capacity, increased storage capacity, higher switching capacity and improved in-service performance (ISP). AXE is fully scaleable and can be dimensioned to offer costeffective support for all sizes of network applications. 6 EN/LZT R4A

7 1 Introduction to AXE System The AXE 810 system further strengthens AXE s position as being a leading switching system and telephony server node plus a vehicle for migration to multi-service and 3G networks. Other emerging Ericsson system platforms will gradually supplement AXE on the Server layer and the Media Gateway layer. AXE is designed to meet the signaling and switching standards recommended by ITU, ETSI and ANSI as well as national standards such as those in China and Japan. The main features of AXE are as follows: AXE modularity SYSTEM ARCHITECTURE An Open Modular Architecture Meeting network operators requirements AXE as a telecommunications node The AXE system is designed using the most advanced technology available and incorporates many unique telecommunications-specific techniques developed by Ericsson to meet the rapidly changing demands of its worldwide customer base. Recent developments have led to a system architecture that is becoming increasingly more open. The philosophy behind AXE is modularity. The modularity concept provides the means by which current and future system development will lead to an open architecture, shorter time to market and easy migration into evolved network architectures. Modularity means ease of handling, reduced operational costs and the flexibility to adapt to the changing world of voice, data, video, Internet and multimedia communications. Modularity can be expressed in terms of: Multifunctionality Application modularity Functional modularity Software modularity Technological modularity Hardware modularity EN/LZT R4A 7

8 AXE Survey Multifunctionality Application modularity Functional modularity Software modularity Technological modularity Hardware modularity Multifunctionality means that the same AXE system can be used in all applications, from small local nodes up to large international switching centers. Business communication, ISDN, mobile subscribers and Intelligent Networks are supported in rural, urban, suburban and metropolitan areas. Application modularity makes it easier to combine different network applications in the same node. The AXE is based on Ericsson s Application Modularity (AM) concept. AM allows existing software to be reused, while enabling practically effortless portability of functionality between the different AXE product lines. Different parts of AXE are defined in terms of the functions they perform. This means that functions can be added, deleted or modified without disturbing other parts of the system. Software modules are programmed independently of each other with different modules interacting by means of standardized software interfaces. Isolated faults in one software module will not distort data belonging to other modules, ensuring a high level of software security. The AXE is an open-ended system, which allows new technologies and functions to be added as required. Such technology can be introduced into one part without affecting the other parts of the AXE Hardware modularity refers to the AXE packaging system or BYB structure. The packaging system consists of hardware, which is designed, in modular units offering a high degree of flexibility for installation and/or expansion, or rearrangement. Different packaging methods are available today. BYB 202 and BYB EN/LZT R4A

9 1 Introduction to AXE System STRUCTURE OF AXE The AXE system structure can be viewed as consisting of a number of different levels. System Level 1 is the highest system level at which nodes and networking configurations are defined. System Level 2 Depending on which system structure is used, subsystems are combined to form APT and APZ in non-am based systems, and application modules, resource module platform (RMP) and existing source system (XSS) or the common name system module is used in AM-based systems. See Figure 1-3. Subsystem Level is divided into a number of subsystems that support the applications and the Control System. Related functions are grouped together into a single subsystem, for example, traffic control functions are located in the Traffic Control Subsystem (TCS). Set of Parts Level includes similar functions within a subsystem grouped together to form what is known as a Set of Parts. Function Block Level. The functions allocated to a particular subsystem are further subdivided into individual function blocks. Each function block constitutes a well-defined entity containing its own data and a strictly defined signal interface. Function blocks are the basic building blocks of the AXE and each block is entirely defined by its software and hardware interfaces to other function blocks. Function Unit Level. Each function block is made up of function units and may consist of: A hardware unit. Non-AM based AXE systems A regional software unit, which deals with activities such as the scanning of hardware devices and protocol handling. A central software or a support software unit which is responsible for the more complex analysis functions required as calls set up in the system. AXE System is structured hierarchically into a number of functional levels. See Figure 1-3. EN/LZT R4A 9

10 AXE Survey Non-AM based AXE AM based AXE AXE AXE System Level 1 APT APZ AM XSS RM APZ System Level 2 Subsystem Level Set of Parts Level Function Block Level AXE Platform Function Unit Level Figure 1-3 Hierarchical structure of AXE Systems APT/APZ AM based AXE systems At, System Level 2, the AXE system is divided into two parts: APT, which is the switching part. For example, APT provides the switching functions needed to implement a PSTN local exchange or node. APZ, which is the control part. APZ is the computer system that runs the software programs controlling the operation of the switching part. APT and APZ are in turn divided into subsystems, each of which has a specific function. The name of each subsystem reflects its function. For example, the group switching subsystem (GSS) is the central switching part of the AXE system. APT and APZ are implemented in software and hardware. The application modularity structure is based on the principles used in communication networks. For example, in order to provide services to end-users, the network nodes must be able to interwork. This interworking is achieved by using common protocols and interfaces. Similarly, each application module (AM) is a self-contained product and is effectively decoupled from other AMs. For communication between AMs there are well-defined protocols and interfaces. AM protocols are of the 10 EN/LZT R4A

11 1 Introduction to AXE System peer-to-peer type, which in principle implies that geographical distribution in the communications network is supported. AM, in simple terms, is a set of well-defined principles for building and implementing software applications. The result is a set of independent software modules that can be developed, compiled, tested and installed without affecting other modules. AMs communicate with one another or with the Existing Source System (XSS) via the communication services included in the Resource Module Platform (RMP). This communication is governed by, strictly defined interfaces and protocols. Application Modules can be reconfigured or upgraded without affecting other related applications. AM AM AM AM XSS APSI RMP RM RM RM RM RM RM APZ Figure 1-4 Application modularity components Communication between these system modules is via the Application Platform Service Interface (APSI). The Application Modules implement application-specific functions for different telecommunications applications. XSS implements the PSTN application. The different RMs implements the majority of the functions that are common to all applications, such as Common Channel Signaling and communication between System Modules. The APZ Control System supports the entire system, which is responsible for processing, operating system and I/O (Input/Output) functions. AXE s software structure is similar to a distributed database in which each module or object operates with its own data. The main software modules are classified as being regional, central or adjunct/support software units that are stored in the Regional Processors (RP), the Central Processor (CP), and the Adjunct or Support Processor (AP/SP), respectively. EN/LZT R4A 11

12 AXE Survey Existing source system (XSS) Resource module platform (RMP) AM simplifies the process of combining different applications to suit the requirements of a particular AXE node, that means, existing, well proven, software can be reused. Services can be ported from one AXE product line to another at minimum cost. The bottom line is that AM results in reduced lead-times. It cuts user cost-of-ownership, protects existing customer investments in AXE software and enables new services to be introduced faster. Flexibility is also provided so that system modules can be arranged to suit a variety of applications. In other words, every AXE system is simply a combination of the associated function blocks required for a particular application. The main purpose of the XSS is to reuse existing and proven software. The XSS appears to other AMs as just another AM. The XSS may be modeled to provide any set of services or applications, for example PSTN, PSTN/transit, MSC etc. This coordinates the system for the application modules. All hardware required by AMs is provided to them by RMP. This hardware may be physically located in RMP or in the XSS. The Resource Module Platform, RMP provides a connection service to the AXE Group Switch, co-ordinates common resources, supports communications between application modules and supports the common services used by XSS (Existing Source System) and the applications modules. Examples of such services are charging and connection resource coordination. RMP also supports communications between AMs. RMP can also provide connectivity to other switches. For example, RMP provides an interface between an ATM switch and the Regional Packet Switch Platform, developed by Ericsson, to enhance ordinary data communication applications such as data over GSM as well as Internet. The Resource Module Platform, RMP, consists of a number of Resource Modules (RMs) system modules that are utilized in all AXE product lines both fixed and mobile. In particular, these RMs support the Application Modularity Architecture. RMP, on the other hand, plays a vital role in the move towards opening up the AXE architecture. 12 EN/LZT R4A

13 1 Introduction to AXE System Examples on different RMs COMRM Communication RM Support the communication between RMs CONRM Connection RM Connection services, for connection through the Group Switch, GS. GS connections, Announcement machines, Conference-Call Device, CCD are handled by this RM. NAPRM Network Access Products RM Exchange terminals, ET, ATM Link Interface, ALI. OMRM Operation and Maintenance RM Functions for the protection of the system, for example load control, event reporting PDRM Pooled Devices RM PDSPL applications, such as KRD, CSK, CSFSK Resource Module Subsystems CCS CHSS COMS COSS ESS-R GSS OMS-R Common Channel Signaling Subsystem Charging Service Subsystem Communication Subsystem Connection Service Subsystem Extended Switching Subsystem Group Switching Subsystem Operation and Maintenance Subsystem Application platform service interface (APSI) The Application Platform Service Interface (APSI) is a system interface that offers client-server services to applications (the clients). APSI services are either implemented in RMP or XSS. These services are required for the coordination of the common EN/LZT R4A 13

14 AXE Survey resource that may be utilized by the different AMs. One example of a common resource is the Group Switch. APSI services: MAIN BENEFITS OF AXE 810 Increased capacity Connection functions include the connection between two points and between multiple subscribers or announcement service terminals. Common Channel Signaling in accordance with international standards, for example, ITU-T and ANSI, and national standards such as those in China and Japan. Internal Communications Support for AMs, that only communicate through RMP they are unable to communicate directly with one another. RMP has a common set of AM communication services for traffic handling and for operation and maintenance. Co-ordination of resources that are common to several AMs. As functionality may be shared between AMs, they will often need common resources. RMP maintains an overview of the common resource. Since its original introduction, the AXE has been improved continuously. The main benefits of the new AXE hardware and software are many but this module tries to capture the very essence of it. As well as providing dramatic physical and operational benefits such as substantially increased capacity, a much smaller footprint and lower cost of ownership the AXE hardware and software architecture is increasingly becoming more open. The main benefits are: This means that customers can build larger switches and in that way decrease their costs for the network (each site costs money in many different ways). In the diagram shown below the AXE 810 is compared with the previous AXE (BYB 501) generation. Larger processing capacity is provided on all levels 14 EN/LZT R4A

15 1 Introduction to AXE System A new Adjunct Processor Group, the APG40, which is the hardware base for the new Adjunct Processor Module (APM) as a platform for management and post processing type applications is introduced. The APG40 targets increased capacity for demanding charging applications. A new, completely open and cost-efficient I/O application, APIO, is also available. In comparison with its predecessors the APG30 and the IOG20, the APG40 has about 3 times higher performance in data throughput and system reload speed. 4 Relative Capacity Capacity CP/APZ Capacity CP/APZ IO Throughput Regional Processors Switch ports Figure 1-5 System capacity The RPG3 replaces the RPG2 and has three times the processing capacity of the RPG2. The APZ is an upgrade of the well-known APZ Central Processor. The APZ is offered along with new nodes and as an upgrade to existing installations. Replacing a few boards, upgrades an existing APZ to an APZ , thereby providing existing nodes with significantly higher capacity. The APZ is a high-capacity processing platform, partially based on industry-standard high-end microprocessors, and designed to handle applications that require very large processing capacity. EN/LZT R4A 15

16 AXE Survey Figure 1-6 Reduced footprint and increased capacity Up to 512 k 64k switching ports can be provided High- speed network interfaces High - speed O&M communication channels Increased reliability This means that Ericsson's customers can get a more reliable network with a minimum time needed for software maintenance. A more reliable network will also increase the revenue in the customer s networks. In-Service Performance The previous operating system, APZ 10, included substantial CP and RP system improvements in the area of software upgrades (for example., Function Change). System Down Time Minutes/exchange/year BYB 202 BYB 501 AXE 810 Figure 1-7 System Down time 16 EN/LZT R4A

17 1 Introduction to AXE System Reduced cost of ownership The APZ 11 operating system further reduces the System Down Time, SDT compared to previous improvements obtained by APZ 10. The system provides a minimum of disturbances at planned upgrades and very reliable hardware Reliable components and pooled devices mean that fewer site visits are required; thereby decreasing repair and spare part costs as well as maintenance staff costs. As hardware shrinks, power consumption and cooling requirements go down as well. Relative Cost BYB 501 = 100 Power Footprint HW Repairs Board Types Figure 1-8 Cost of ownership This means reduced cost of ownership. The number of board types have also been decreased so spare part stocks can be reduced meaning more money for other things than spare parts. Already at a low level, AXE s cost of ownership is significantly further reduced as illustrated in the diagram to the right - shows the reductions for an average node as compared with the previous AXE BYB 501 generation. Annual operational cost reductions for an average sized node can amount to as much as 7,000 USD as compared with the BYB 501 generation and as much as 50,000 USD as compared with the BYB 202 generation. Full remote management can be provided. EN/LZT R4A 17

18 AXE Survey Loadable software. Programmable devices can be remotely loaded with new software making it easy to adapt their functionality to changing requirements. Operation and Maintenance tools Lower O&M Costs. A number of hardware features facilitate easier operation and maintenance. These same features also make it easier to centralize O&M activities; so that less complex O&M activities can be performed by less qualified staff located at remote O&M sites. Using existing O&M Competence. The hardware is managed as part of the established AXE architecture. Staff trained to work with AXE can operate the AXE 810 using established procedures. Existing competence in operating and maintaining AXE can be reused. Migration to 3G Ericsson's ENGINE concept as well as next generation mobile systems mean openness to next generation networks for example 3G mobile, UMTS and CDMA2000 By upgrading AXE with the new hardware, a path to secondgeneration network is secured. Multi-service networks and Server - Gateway architecture are provided Shorter time to RFI (Ready For Installation) Scalability Reduced size and better standardization of nodes makes the order process within Ericsson simpler. It is almost that one size fits all. AXE is scalable from small, low-end systems, up to extremely high-capacity nodes. Small but powerful one-cabinet nodes can be provided. For example a mid-size GSM-BSC node can be configured to not exceed the footprint limit of one cabinet. A High-end TDMA-MSC node configured not to exceed the capacity limit set by the APZ Central Processor. Up to nodes with 512k 64kbit switching ports Extendibility by self contained generic magazines 18 EN/LZT R4A

19 1 Introduction to AXE System Multi Application Platform Open Architecture Fast and Simple Installation Carrier-Class System AXE 810 can be used for a number of fixed and mobile applications. Local Exchanges Transit Exchanges Telephony Servers Mobile Switching Centers - GSM, TDMA, CDMA, PDC Base Station Controllers Application Modularity Adjunct Processor based on industry standard hardware and operating system Industry standard communication protocols Nodes and Extensions delivered "pre-installed" Plug and Play support is provided Rapid installation. The hardware is cabled and tested in the factory prior to delivery. This reduces installation time and equipment costs. Small, maneuverable cabinets, improve the ease of installation. All external cabling can be installed in the cable distribution system before the cabinets arrive at the site. As in the case of the BYB 501, the mechanical endurance characteristics of the newer generation permit easy cabinet delivery to the site. Fewer board types. The total number of board types has also been reduced. This decreases spares storage space requirements to a minimum. It may be practically possible to carry all, or most, of the board types in a service car. Indirect storage costs of spare parts such as overheads, facilities, personnel and administrative systems, can often amount to 30% or more of the storage value, so that network operator cost savings can be considerable. Electro-Magnetic Compatibility (EMC) is the ability of equipment to coexist with other equipment as regards their common electromagnetic environment. A fundamental principle EN/LZT R4A 19

20 AXE Survey HIGH-LIGHTS OF AXE 810 in all hardware design is to neutralize interference as close to the source as possible. AXE is compliant with all international and national Electromagnetic Compatibility, EMC, and Product Safety directives. Standard BYB 501 cabinets are earthquake-proof. In this module the most important changes and their impact on the total system performance are described. The main motive with AXE 810 project was to develop cost and hardware rationalized products for the Generic Ericsson Magazine, (GEM). Products introduced in AXE 810 are: New Central Processor There is a new CP developed called APZ with 70% more capacity than APZ The processor is also prepared for a new type of inter-processor network. New Regional Processors for example RPG3, RPI All types of regional processors get more capacity in less space. New APG, Adjunct Processor Group A new more powerful adjunct processor is developed (APG40). This means more storage capacity, faster reloading and more processing capacity for a number of applications. A new GEM subrack The GEM subrack (Generic Ericsson Magazine) can house the group switch and a large number of boards such as ET155, Transceivers and Echo Cancellers. A new Group Switch, GS890 A new high-capacity group switch with distributed architecture is included. The switch is true non-blocking switch with a maximum capacity of 512k. One-board ET155 An ET155 is now available in one-board solution decreasing the size of the exchange significantly. The ET155 is also adapted to the new GEM subrack. 20 EN/LZT R4A

21 1 Introduction to AXE System SYSTEM CHARACTERISTICS New Transcoders TRA R6 and Echo Cancellers in Pool, ECP5 New hardware with increased capacity adapted to the new GEM subrack. The comparison below is made with respect to the previous AXE generation, the so-called BYB 501 generation. The BYB 501 generation as such offered very significant improvements in relation to its predecessor the BYB 202 generation. A fully modular design with industry-standard interfaces means that AXE can incorporate new technology and third-party products, giving users the flexibility to customize their networks in order to meet rapidly changing multi-service market requirements BYB 202 = 100 BYB 501 AXE HW Repairs Power Board Types Footprint Figure 1-9 Comparison between BYB501 and AXE810 DIFFERENCES COMPARED WITH BYB 202 Many customers still have the old AXE built with the BYB 202 hardware (the blue cabinets referred to as AXE Classic in some cases). For them to upgrade to the new AXE 810 means enormous changes in footprint, power consumption and capacity. The most important changes when upgrading from BYB 202 are shown below. EN/LZT R4A 21

22 AXE Survey Changes in footprint The change in footprint is dramatic if upgrading from BYB 202 to the new AXE 810. Changes in power consumption Changes in board types Changes in processor capacity Figure 1-10 Footprint changes when upgrading from BYB 202 The changes are in the range of 1:10 for an average node. To get the exact figure, you must know exactly what type of node it is (for example Transit exchange, GSM MSC or TDMA MSC). As the hardware shrinks to very small amounts, the power consumption does that as well. However, the power does not go down as much as footprints as circuits are packed and still require much power. As an example, forced cooling is mandatory in the new AXE 810 because of the dense building practice. The number of board types in system, affects spare parts stocks and in that way the cost of ownership for a system. If a system has fewer board types than another system, it is less costly to own. The number of board types in reduced dramatically when upgrading from BYB 202 to the new AXE 810. If an operator has a system based upon BYB 202, he probably also has an old Central Processor. By upgrading to the new AXE 810, the processing capacity is increased a lot. Please study the figure below. 22 EN/LZT R4A

23 1 Introduction to AXE System Changes in Group Switch capacity Figure 1-11 Capacity is increased when upgrading CP There will also be substantial increase in capacity in other parts of the APZ. As an example, the new RPG3 has 10 times more capacity than the RPD used in BYB 202 hardware with a lower power consumption and smaller footprint. The maximum size of a group switch in BYB 202 was 64K (65536 channels of 64 kbit/s). It was possible to connect a subrate switch to the group switch, which could be used to switch 8 kbit/s. The subrate switch is used in mobile applications to save bandwidth as mobile phones code with lower rates than 64 kbit/s. Figure 1-12 Changes in maximum Group Switch size when upgrading from BYB 202 EN/LZT R4A 23

24 AXE Survey A group switch in the new AXE 810 is strictly non-blocking which was not the case with the older group switch in BYB 202. This means that a 64K switch had a dimensioning factor of some 0.8 meaning that the real size was not more than around 50K. The figure above shows the differences when upgrading the group switch. DIFFERENCES COMPARED WITH BYB /1.4 Changes in footprint The difference in metrics is also quite big when upgrading from BYB 501 with the 1.3 or 1.4 hardware to the new AXE 810. In the following parts dome metrics for customers having BYB 501 hardware and they would like to upgrade or replace hardware is presented. Please note that the figures are valid for an average node and the exact figures have to be calculated depending on the existing node type (for example TDMA MSC or GSM MSC). The average decrease in footprint is around 50%. This means that the size is reduced to half. As BYB 501 in version 1.3 or 1.4 already are quite small, this further reduction is size is quite astonishing. Please study the figure below. Changes in power consumption Figure 1-13 Reduction in footprint from BYB 501 (1.3) to the new AXE 810 The power has not been reduced in the same amounts as footprint. The answer to that is that circuits have been more packed in the new hardware and therefore reducing space more than power. However, some 30% reduction from a rather low level is quite good. 24 EN/LZT R4A

25 1 Introduction to AXE System Changes in board types Changes in Group Switch Capacity The number of board types in a system, affects spare parts stocks and in that way the cost of ownership for a system. If a system has fewer board types than another system, it is less costly to own. The number of board types in reduced dramatically when upgrading from BYB 501 (1.3) to the new AXE 810. The maximum size of a group switch in BYB 501 was 128K in ( channels of 64 kbit/s). It was possible to connect a subrate switch to the group switch, which could be used to switch 8 kbit/s. The subrate switch is used in mobile applications to save bandwidth as mobile phones code with lower rates than 64 kbit/s. A group switch in the new AXE 810 is also strictly non-blocking which was not the case with the older group switch in BYB 501. This means that a 128K switch had a dimensioning factor of some 0.8 meaning that the real size was not more than around 105K. The figure below shows the differences when upgrading the group switch. Figure 1-14 Changes in maximum Group Switch size when upgrading from BYB 501 (1.3/1.4) The subrate solution in the new group switch is quite different from the subrate solution in the old group switch. Please also note that it is not possible to have a 512K group switch with the central processors available today as the capacity of the CP sets a limit below 512K. However, future CPs will be able to take full benefit from the large group switch. EN/LZT R4A 25

26 AXE Survey AXE SYSTEM COMPONENTS APT 1.5 HSL S7 ET155-1 RPI GS890 GEM ECP5 RPI TRA R6 RPI CL890 GDM ETC5 ALI ETC.. PDSPL M-AST APZ CPG APZ CPG APZ APZ 11 CPG APM APG33 APG40 RPP RP4 RPG3 EMRPI Figure 1-15 AXE System Components APG ALI CP ECP EMG EMRPI ET M-AST PDSPL RPx RPP TRA Adjunct Processor Group ATM Link Interface Central Processor Echo Cancellers in pool Extension Module Group Extension Module Regional Processor Integrated Exchange Terminals Modula AST (Announcement Service Terminal) Pooled Digital Signaling Platform - Loadable Regional Processor... Regional Processor Platform Transcoders HARDWARE ARCHITECTURE Figure 1-16 provides a simplified overview of the hardware architecture in AXE 810. Group switch, GS is generally seen as the hub around which the system is built. The Group Switch performs functions such as selection, connection and disconnection of speech or signal paths that pass through the group switch as well as connection or disconnection of telephony devices to the speech or signal path. GS includes also an integrated subrate switch. Furthermore, the Group Switch provides supervision of the digital links connected through the switch, 26 EN/LZT R4A

27 1 Introduction to AXE System thereby maintaining a stable and accurate clock frequency for the purpose of network synchronization. Key Components RPI TRA RPI ECP ALI AST ATM Link Interface EMB ET DL RPI GS PDSPL ET STM RP RPP RPG RP RPB APG APG CP IPN Inter Platform Network Figure 1-16 Hardware architecture Regional Processor Bus, RPB is primarily used for communication between the Central Processors and the Regional Processors. The RPB enables single-board or onboard application RPs to be housed in the same magazine or board as the devices that they control, thus minimizing hardware and cable interconnections between hardware devices. The RPB has a capacity of 10 Mbit/s per branch. Duplicated connections to the RPs are made in the backplane and thereby facilitating disturbance free repair, installation and future expansion. Extension Module Bus, EMB. The switching hardware may be arranged into groups called Extension Modules (EMs) that are Plug-In Units connected to the Regional Processor (RP) via an EM bus. The EM bus between the RP and the EMs exists only in the magazine back plane, thereby doing away with the need of EM bus cables. The address of each EM is coded in the magazine back plane thereby eliminating the need of EM address plugs. Inter Platform Network, IPN is introduced for the APZ and the APZ central processors as well as for the APG40. The initial use of IPN is to improve system backup and reload performance. A second advantage of the IPN is the possibilities that it presents in connection with the EN/LZT R4A 27

28 AXE Survey building of larger systems - whereby the AXE is combined with other components such as the TSP or the AXD 301 for the creation of a Hybrid System. IPN provides a 100 Mbit or 1 Gbit Ethernet communication channel providing higher short-message rates and increased reload and backup throughput. Digital Link, DL is the interface between the Group Switch and the configured devices. A few DL versions exist with different capacity where the DL34 is a new interface, optimized for communication between the new Group Switch (GS890) and the various high-speed devices. Capacity is variable in steps of 128 time slots, covering a range of from 128 to 2096 time slots. Maximum capacity, including other payloads such as signaling, is kb/s channels. Central Processor, CP is duplicated, thereby offering a high level of hardware fault tolerance as well as a high processor capacity. The two-processor sides operate such that, at any given time, only one of the processor sides controls the applications hardware. In the event of a fault in the operational side, control may be swapped to the other side (if the fault is considered serious) with minimum, or no, impact on traffic handling. Regional processors, RP/RPG/RPP/RPI are used for routine repetitive processing, application hardware control and processing-intensive tasks such as protocol handling. The architecture allows full scalability, that means, the number and type of regional processors are adapted to the need. Adjunct Processor Group, APG is the hardware platform for Adjunct Processors. The APG, which is based on commercially available hardware and operation system, forms a high availability platform for near real-time, capacity-demanding, management processing tasks. APG replaces the Support Processor Group (SPG). Transcoders, TRA used in conjunction with for example GSM and TDMA systems for speech processing. Same hardware platform providing 192 speech channels per board is used independent of standard. Echo Cancellers in Pool, ECP providing exceptional speech quality. The ECP is based on the same hardware platform as the TRA. The echo canceller application offers 128 channels per board. Pooled Digital Signaling Platform - Loadable, PDSPL constitutes the hardware platform for the majority of Tone 28 EN/LZT R4A

29 1 Introduction to AXE System The APZ Control System and Signaling equipment. The PDSPL consists of a single board to which a variety of application software can be downloaded. Exchange Terminals, ET includes 1.5, 2 and 155 Mbit network interfaces. ATM Link Interface, ALI is a fully integrated AXE device. It contains an optical 155 Mb/s ETSI STM-1 interface, which terminates incoming ATM cells that are carried in the VC-4 containers (level 4 Virtual Container) of the STM-1 frames. ALI is based on RPP. An important factor behind AXE s flexibility is the APZ Control System Architecture that is a two-level architecture including both central and distributed control. It is an approach that ensures high reliability and efficient call handling. The APZ, the heart of the AXE platform, has been continually developed over many years to provide a flexible and a powerful control system for a wide range of communications applications. The development effort has always prioritized a high level of backward-compatibility with previous generations, thereby making the upgrade of the existing AXE installations troublefree. APZ is both operationally reliable and easy to manage. Like the rest of AXE, the APZ also exhibits a modular structure. The main benefits of the APZ system are: Well proven multi-application system Handling is independent of processor variant Hardware platforms that offer a range of performance profiles High hardware reliability Redundancy in all critical units Advanced functions for graceful recovery following software or hardware errors Advanced functions for on-line and remote software upgrades. The main architectural characteristics of the APZ processor system are: Hierarchical processor structure an optional number of Regional Processors may be connected to a powerful Central Processor. EN/LZT R4A 29

30 AXE Survey Supplementary industry-standard computing equipment in the form of an Adjunct Processor. This is used for near realtime processing, for example, the formatting of charging data. EMG EMRPI STR APG Adjunct Processor Group CP Central Processor EMG Extension Module Group EMRPI Extension Module Regional Processor Integrated RPx Regional Processor... RPB RP Bus STR Signal Terminal Remote TCP/IP Ethernet APG RPG RP RPP RPI RPG RPB CP IPN - Ethernet Figure 1-17 The APZ control system Functional modularity including high-level language programming. The Central Processor, CP is duplicated, offering high hardware fault tolerance. In the event of a fault, control may be swapped to the other side with minimum or no impact on traffic handling capability. The Central Processor includes three logical stores: The Program Store (PS), which represents the program area of the function blocks. The Data Store (DS), which represents the data area of the function blocks. The Reference Store (RS), which contains program and data addressing information for each function block. The operating system uses two tables to point to the absolute addresses of programs and data areas of the receiving block. Thus, neither the designer nor the maintenance technician need consider the physical location of the software. This structure, contains three logical stores, combined with a special addressing mechanism, is fundamental in providing the level of software modularity attained by the AXE platform. 30 EN/LZT R4A

31 1 Introduction to AXE System Programs and data are automatically allocated to absolute addresses during the process of loading them into memory. The Regional Processors, RPs, are used for routine repetitive processing and for processing intensive tasks such as termination of the lower protocol layers. The Adjunct Processor, AP offloads capacity-demanding data processing tasks from the central processor, and assigns them instead to a dedicated processor, thereby freeing up the central processor for traffic handling tasks. The adjunct processor replaces or supplements the Support Processor (SP) used in the IOG (Input/Output Group) system. The adjunct processor is based on commercially available hardware as well as operating systems that are compliant with telecommunication requirements. The Adjunct Processor provides: Increased network efficiency through the combined use of an open interface protocol and an Ethernet link for the fast and reliable transmission of output charging data to the billing center. Decreased Central Processor load by formatting charging data external to the Central Processor. These increases call handling capacity allowing the operator to add more subscribers to the network. Improved I/O functionality and access to the AXE, featuring fast terminal communication rates, enhanced backup file and alarm handling. The result is lower Operation and Maintenance costs. Open system including the capability to support the introduction of new technologies for operation and maintenance and services. Fault-tolerant architecture supporting a hot swap capability to ensure a robust applications processing environment. The hardware is both scalable and redundant, which allows cost-effective and worry-free operation. Formatting and Output Subsystem (FOS) and Statistics and Traffic Measurement Subsystem (STS) STS and FOS are implemented in APG40 Formatting and Output Subsystem (FOS). The Central Processor collects charging data and sends it to the APG where the data is recorded in a safe file storage area and is then passed EN/LZT R4A 31

32 AXE Survey on to a formatting process for conversion to an output format. The formatted data may then be forwarded to external billing systems. Statistics and Traffic Measurement Subsystem (STS) provides for the collection, storage, and presentation of statistical data. STS collects data from different counters that support functions such as Authentication, Local Number Portability, and Traffic on Routes, Size Alteration Events, Multi-Exchange Paging, and Subscriber Activities. One advantage of STS is the reduction of Central Processor load. The Central Processor collects counter data that is passed in a raw data format to the STS Subsystem residing in the APG - where it is stored, formatted and output to those requesting statistical information Datacom and Packet Switch Support INTER PLATFORM NETWORK The AXE platform is increasingly being used for the support of both datacom and packet switching applications. One recent example is the PCI-based Regional Processor Platform, RPP, and the Ethernet Packet Switch Board, EPSB. RPP is targeted to support datacom related telecommunication applications. RPP offers a range of open hardware interfaces, a range of software applications plus a complete development environment. Ethernet packet switch board (EPSB) supports applications that are distributed over a number of RPPs and which therefore require interwork support. Internet Access Server, an RPG-based function, enables the concentration of ISDN data traffic early at the point of access. Subscribers may be connected via ISDN (64 kbps) or via modem. The access server makes it possible to provide decentralized access points that are integrated into the public network exchanges for the different service providers. As the access server can be shared by multiple Internet Service Providers (ISP), it can act as a common point of presence for any ISP within the public switched network. An Ethernet based, 100 Mbit or 1 Gbit, Inter Platform Network, IPN, is bringing in an industry standard, high capacity interface into AXE. 32 EN/LZT R4A

33 1 Introduction to AXE System As illustrated in the Figure 1-18, IPN has a number of applications: CP-AP communication. The improved bandwidth can be used to decrease system backup and reload times. Communication between AXE/CP and another platform (for example, the AXD 301). CP-CP communication within a future multiple CP-cluster. Functionally, IPN replaces the 10 Mbit STOC (Signaling Terminal Open Communication) used earlier as an internal AXE Ethernet termination. Currently the following proprietary application level communication protocols over IPN are available: MTAP, Message protocol to Adjunct Processor transfers messages of variable length from a CP application to storage in AP environment where the messages are organized in message stores. One usage of MTAP is to provide an interface in the CP to the file system in the AP. FMI, File Management Interface is the traditional file system interface in IOG and is available in the AP to provide a backwards compatible file system interface for the applications in the CP that is not yet adopted to the MTAP interface. JTP, Job Transfer Protocol is a generic protocol between CP and AP used for applications that in one processor that wants to initiate tasks in the other processor AP AP Other Systems, e.g. AXD 301 Ethernet switch IPN /33 CP IPNA IPNA Figure 1-18 Inter Platform Network EN/LZT R4A 33

34 AXE Survey Server Gateway Architecture ADP, Alphanumeric Device Protocol is used for transferring alphanumerical information (command and printouts) from the device block in the CP to the Telnet application in the AP TRH, Transaction Record Handler protocol supports the communication needs of the AXE - AXD 301 control interface that is utilized in the ENGINE solution Other application communication protocols will be made available as required in order to generally support the distribution of functionality. The introduction of new AXE communication services makes it possible to combine AXE functionality with that found in other platforms. This ability supports stepwise, or phased, migration activities as well as reusability. The communication services all run on top of industry-standard Ethernet. A number of services add functionality on top of TCP/IP - one of them adds functionality to raw Ethernet. Ericsson can thereby select and layer different commercial standards on top of one another in order to suit the needs of the application. AXE 810 supports the emerging network architecture in which a distinction is made between Servers and Gateways. AXE 810 supports standard protocols for signaling between different nodes in this network architecture. Telephony server an example One example of AXE used as a telephony server is the ENGINE Integral solution. In this case the telephony server consists of AXE 810 and AXD 301 systems. The AXE part handles call control and telephony functions, whereas the AXD 301 part provides the interface to the ATM network and contains a switch emulator (SE) and media gateway function that connect to an integrated resource module in the server. The switch emulator is controlled by AXE from the resource module platform (RMP), which separates control of the switch from applications. The resource module platform can thus be extended to control a separate ATM bearer network. An internal system protocol, used between AXE and AXD 301, controls the switch emulator. 34 EN/LZT R4A

35 1 Introduction to AXE System The group switch in AXE, which is used for connecting announcements, conference bridges, signaling terminals, and so on devices, enables the reuse of existing devices in AXE. This translates to lower investment costs when operators upgrade AXE to serve as a telephony server. The AXE system contains the software for call control (number and routing analysis). It also contains the telephony functions used in circuit-switched telephone networks (charging and accounting services, and different kinds of signalling support). The use of AXE as a component of the telephony server guarantees smooth migration to an ATM-based multi-service network with full transparency of existing telephony functions. Another advantage of using the AXE system as a basic component in the server is that it can be combined with the handling of normal circuit-switched traffic. This capability is used for connecting trunks with in-band signaling directly to the group switch. Thanks to the widespread deployment of AXE, a multitude of market variants of signaling systems is supported, which also means that the complexity in the media gateways can be reduced. EN/LZT R4A 35

36 AXE Survey PRODUCT LINES Ericsson product range for fixed and mobile network applications is composed of a number of product lines. Fixed network product lines Mobile product lines WCDMA systems AXE Local AXE Transgate AXE TransLocal CME 20/CMS 40 CMS 30 CMS 8800 CMS 45/89 CMS 8810 Figure 1-19 Product lines Product lines in the fixed network AXE Local Product lines in the fixed network include: AXE Local AXE Translate AXE Tran Local The AXE architecture is capable of being deployed at local exchange level covering locations ranging from high-density urban areas to low density rural areas. AXE Local supports the following: Communications applications, such as PSTN, ISDN, business communications, intelligent network and the Internet (with a special access server) Services from basic telephony, data and video transmission to the most complex international business communications services Wired access, including copper and fiber 36 EN/LZT R4A

37 1 Introduction to AXE System Radio access, including radio in the local loop (RLL) products and cordless telephony products Standard interfaces and protocols, such as V5.1, V5.2, QSIG, and SS No.7 AXE Transgate The AXE architecture is capable of being deployed at national and international transit level, supporting PSTN, ISDN, intelligent network and business communications. AXE Transgate is capable of implementing the following network nodes: International gateway National transit Service control point (SCP) Service switching point (SSP) Signaling transfer point (STP) Service switching and control point (SSCP) Operator exchange (operator AXE or OPAX) AXE Transgate has a number of important features for the network operator: ISDN primary rate access (PRA) Supports American National Standards Institute (ANSI) and International Telecommunication Union- Telecommunication Sector (ITU-T) SS No.7 signaling Charging and accounting Dynamic routing International virtual private network (IVPN) Digital circuit multiplication equipment (DCME) Echo cancellers AXE Transgate can also provide transit functions in mobile networks. AXE TransLocal The AXE architecture, which implements AXE Local and AXE Transgate, is capable of supporting a combined node called the EN/LZT R4A 37

38 AXE Survey Mobile Product Lines Digital product lines AXE Translocal, which contains products from both product lines. AXE TransLocal meets the demand from new network operators who do not want to have separate local and transit nodes (national and international), particularly when starting up a new network, when the level of subscriber traffic is at its lowest. This product line is also capable of expanding as the network operators business grows. TransLocal, supports the following applications: PSTN ISDN Intelligent network Business communications Internet AXE TransLocal also includes features such as: Digital circuit multiplication equipment (DCME) ANSI and ITU-T SS No.7 functions for national and international signaling Echo cancellers In the cellular mobile environment a product line refers to an entire system, which implements a particular standard. The main product lines in digital cellular mobile communications are: CME 20/CMS 40, which implements the GSM standards at 900 MHz, 1800 MHz and 1900 MHz. CMS 30, which implements the PDC standard. CMS 8800, which implements the D-AMPS standard. All Ericssons mobile product lines are based on the same AXE architecture as the fixed network product lines discussed above. 38 EN/LZT R4A

39 1 Introduction to AXE System CME 20/CMS 40 This product line supports all the network nodes required in a GSM network including the base stations and the operation and support system. Nodes implemented by the AXE architecture are: Mobile services switching center/visitor location register or MSC/ VLR (this can also include a service switching point or SSP function) Gateway MSC (GMSC) BSC/TRC, stand-alone transcoder controller (TRC) and stand-alone base station controller (BSC) Home location register (HLR) Service switching and control point (SSCP), service switching point (SSP) and service control point (SCP) Authentication center (AUC) Inter-working location register (ILR) CMS 30 This product line supports all the network nodes required in a Personal digital cellular (PDC) network including the base stations and the operation and support system. Nodes implemented by the AXE architecture are: Visited mobile services switching center (VMSC) Gateway mobile services switching center (GMSC) Home location register (HLR) Gateway location register (GLR) CMS 8800 Analogue product line This product line supports all the network nodes required in a Digital American mobile phone system (D-AMPS) network including the base stations and the operation and support system. In CMS 8800, AXE architecture is used to implement the following nodes: MSC HLR EN/LZT R4A 39

40 AXE Survey Ericsson also supports all the major analogue world standards with the following product lines: CMS 8800 (Advanced mobile telephone system or AMPS) CMS 8810 (Total access communications system or TACS) CMS 45/89 (Nordic mobile telephony or NMT) WCDMA/UMTS EVOLUTION OF AXE General Historical background The 3G (3:d generation) mobile networks are based on WCDMA/UMTS technology. AXE was originally developed in the early 1970s and has been continually improved since its first release. The development of AXE so far, and its continued evolution into the 21 st century, reflects the changing needs of the information world. Year Event in development of AXE 1975 AXE, the new computer controlled local exchange system, is introduced into the world market The AXE system starts making major breakthroughs in international markets The first completely digital AXE exchange is installed in Finland AXE has now been sold in 63 countries and is used in 22 mobile telephone systems AXE makes its debut in North America Four million AXE lines are installed. This is equivalent to 10% of the world s market Ericsson installs the first GSM system, based on AXE AXE is now installed in 101 countries Million AXE lines are installed. 40 EN/LZT R4A

41 1 Introduction to AXE System Future Development of AXE million AXE lines are installed bringing the total number world-wide to 105 million. Ericsson s mobile networks, based on AXE, are serving 34 million subscribers in 74 countries The number of AXE lines (local and trunk) installed or on order is over 134 million. AXE nodes are deployed in mobile networks in over 125 countries More than 200 million mobile subscribers Figure 1-20 AXE Development AXE is evolving towards a more open system. This includes: Software evolution to application modularity. A hardware development program continuing the process of reducing the footprint and ensuring electromagnetic compatibility (EMC) at board level rather than cabinet level. Processor development including more powerful regional processors and a micro-rp, and more powerful CPs. Maintenance and control of AXE through an industry standard input/output (I/O) system, which is a UNIX, based adjunct processor (AP) programmed in C++, Windows/NT and Java. As well as providing the platform for I/O, AP will be used for other applications, such as charging. A Group switch being developed into a multi-fabric switching platform capable of handling all types of communication formats from narrowband through to broadband. Also, developments in the area of group switch capacity. EN/LZT R4A 41

42 AXE Survey Intentionally Blank 42 EN/LZT R4A