An Introduction to the Ericsson Transport Network Architecture ...

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76 Fig 10 SMUX Control System Hardware implementation TAU MAU AUI LAN Termination Access Unit Medium Attachment Unit Attachment Unit Interface Local Area Network Hardware Platform The management subsystem hardware platform consists of processors at two different levels: - Central Processor (SU) - Unit Processors (UP). In addition, the following equipment may be required for control and operation: - IBM-compatible 386/486 PC (Local Operator's Terminal) - MAU (Ethernet transceiver) for connection to a DCN of LAN type. The SMUX Control System Hardware Architecture is illustrated in Fig. 10. The SU communicates with the UPs via an internal ISO 8482 bus, which is similar to RS-485. The SU implementation is mainly based on the following circuits: -CPU - Ethernet controller (Q3-interface) - RS-232 Communication controller (Finterface) - LAPD Communication controllers (internal communication) - Relay contacts (Station alarm interfaces) - Detection logic (External alarm interfaces) - Program memory - Data memory - Backup memory for non-volatile data. The UP is a general hardware building block common to all transmission printed board assemblies. The UP implementation is mainly based on the following circuits: -CPU - LAPD communication controllers (ECC and internal communication) - A/D and D/A converters, for measurement of laser characteristics, such as input power and laser bias current - Test interface (gains access to UP software for an authorised user) - Program memory - Data memory - Backup memory for non-volatile data. Not all UP circuits have to be present on every transmission printed board assembly. The CPU used both for SU and UPs is the Motorola 68 302, which is a microprocessor optimised for data communication (ISDN) purposes. An IBM-compatible 386/486 PC is used as Local Operator Terminal. The LOT provides the operator with a Network Element view. However, it is possible to manage small networks from the LOT, but of course without network view. To manage a network from an LOT without assistance from the FMAS, communication over the ECCs is used, Box 2. By using ECC it is possible for an LOT to exchange messages with any other SDH NEs within the SDH network. This possibility (of accessing remotely located SDH NEs) is referred to as Remote Login. It will be a valuable feature, especially for early field trials and installations without a complete Network Management System. Software Architecture The SU and UP software in an SMUX forms a loosely coupled, distributed software system organised into a layered structure, where each layer has a well defined task, Fig. 11. Additionally, PC software which is not indicated in Fig. 11 is required for the Graphical User Interface. The SU software layers and their tasks are as follows: ERICSSON REVIEW No. 3, 1992
Fig. 11 SMUX Software Architecture • The SU application software communicates peer-to-peer with the UP's application software • » The SU communicates with the UP's by using an ISO 8482 backplane bus References 1 Tarle, H.: FMAS - An Operations Support System for Transport Networks. Ericsson Review 67 (1990):2, pp. 163-182. 2 Widl.W.: CCITTStandardisation of Telecommunications Management Networks Ericsson Review 68 (1991) :2, pp. 34-51. 3 Widl, W. and Woldegiorgis, K.: In Search of Managed Objects. Ericsson Review 69 (1992):1/2, pp. 34-56. 4 Bergkvist, J. A., Evangelisti, G. and Hopfinger, J.: AXD 4/1, a Digital Cross-Connect System. Ericsson Review 69 (1992):3, pp. 78-68. 5 CCITT Draft Rec. M.3010: Principles for a Telecommunications Management Network. 6 CCITT Rec. G.774: SDH Network Information Model for TMN 7 CCITT Rec. X.200; Reference Model of Open Systems Interconnection for CCITT Applications. - User Access layer Provides external access for an OS or local operator to the management view of the SDH multiplexer. Contains the data communication services for the F, Q3 and ECC interfaces • TMN layer Provides the generalised TMN management view of the SDH multiplexer in the form of a Management Information Base with the managed objects, their attributes, actions, and emitted notifications • SMUX layer Contains a logical SDH multiplexer as specified in CCITT Recs. G.782-G.783. This logical multiplexer can be controlled from the TMN layer and has the standardised automatic behaviour for protection switching and change of synchronisation source - Magazine layer Manages all hardware units in the magazine so that they provide the logical SDH multiplexer transmission services requested by the SMUX layer using the available units, and signal interconnections in the magazine - Unit layer Manages individually each hardware unit in the magazine, ordering changes in the unit, receiving events from the unit and ensuring that the U P software is consistent with the SU software - Base layer Provides process management and communication, drivers for SU I/O ports and communication services between the SU and UPs - Virtual machine layer Provides a real-time, multi-task virtual machine on bare machine hardware. Contains Operating System kernel and low-level hardware interfacing to the SU hardware. The UP software layers and their tasks are as follows: - Unit layer Manages each hardware unit individually, making changes on the unit according to orders from the SU, and reporting events from the unit - Base layer Provides process management and communication, drivers for I/O ports on the unit, and communication services between the UP and SU - Virtual machine layer Provides a real-time, multi-task virtual machine on bare machine hardware. Contains Operating System kernel and low-level software interfacing to the transmission circuits. The PC application software and its purpose are as follows: - Graphical User Interface (GUI) Provides the local operator with a graphical user interface. Summary The control and operation of SDH Network Elements is and will continue to be adapted to the evolving TMN standards. This facilitates their connection to centralised Operations Systems. The implementation of the control system takes into consideration the various demands of Network Elements, ranging in size and complexity from small SMUXs up to large SDXCs. ERICSSON REVIEW No. 3, 1992
Page 1: ERICSSON REVIEW 3 1992 An Introduct
Page 4 and 5: An Introduction to the Ericsson Tra
Page 6 and 7: 60 Fig. 3 AXD 155 system integratio
Page 8 and 9: Control and Operation of SDH Networ
Page 10 and 11: 64 These functions and a number of
Page 12 and 13: 66 to the OS upon detection of a se
Page 14 and 15: 68 BOX 3 The SDH NE MANAGEMENT ORGA
Page 16 and 17: Fig. 4 Control System Architecture
Page 18 and 19: 72 Fig. 6 Software Architecture CSA
Page 20 and 21: 74 Functional requirements Certain
Page 24 and 25: AXD 4/1, a Digital Cross-Connect Sy
Page 26 and 27: 80 Fig. 2 AXD 4/1, System Architect
Page 28 and 29: 82 Fig. 3 Time Space Switch structu
Page 30 and 31: 84 Fig. 4 AXD 4/1 Devices Devices o
Page 32 and 33: 86 The control signals, which come
Page 34: 88 Fig. 8 Protection Switch Unit st

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