The NMS is the operation and maintenance related part of the network and it is needed for the control of the whole GSM network. The mobile network needs to be monitored continuously, and there are several reasons for this. As a result of a successful registration, the network sends the mobile station two numbers that are stored in the SIM Subscriber Identity Module card of the sysyra station.
In such a case, we talk about international roaming leg, which refers to the connection between the home network and the subscriber via a foreign network. It supported only sysra related signalling. Ultimately, it may even be impossible to establish a call. Which of the following are dedicated channels? There are four different types of handover and the best way to analyse them is to follow the subscriber as he moves: Tuning into the network The synchronisation information required by this process is broadcast by the network and analysed by the mobile.
In the worst case an entire burst might get lost. In shstra words, by using a sectorised antenna the covered distance increases. The subscribers may also discover problems that would not sysrra be identified. The result of the analysis is the routing information required for finding the mobile network Public Land Mobile Network, PLMN in which the called subscriber has made his subscription.
It was initially decided that GSM would evolve over time. We could use commercially available processors and write software for it to execute. As a consequence, the connection is handed over to a cell with a stronger signal. Systda Transfer Part layers The lowest level, MTP layer 1 physical connectionsdefines the physical and electrical characteristics.
However, the amount of signalling between the MSC and the VLR is quite heavy and their tasks are so related with each other that it makes good sense to integrate them together. Sending charging data to the billing centre. It has only one basic configuration.
These functional units have independent tasks, but communicate when and as necessary using a common message bus. The solution adopted to overcome this problem is known as adaptive power control. To make sure that the NSS knows whom to charge for the call. The maximum length of a cell broadcast SMS is 93 characters. Since each carrier supports eight channels, we can make a rough estimation that this cell must be equipped with three carriers, that is, three transceivers or TRXs.
The SIM is a small memory device mounted on a card and contains user-specific identification. BTS configurations After all the installation sites have been surveyed, a detailed network plan can be made. EFR coding gives better speech quality at the same bit rate than normal full rate. There is multipath propagation, shadowing and propagation delay. Which of the following is not a signalling function?
Thus a mobile station and the base transceiver station receives the same signal more than once. Parameters that can be used as a basis for charging the subscribers are shown in the following list: Careful network planning is thus a primary aspect of implementing GSM networks. Servers are also provided and consist of a communications server, a database server and a standby server or combinations of these.
Identifying the calling subscriber. One of the main advantages of this system was that signalling did not have to go along the same path as the speech. He might be in his room, in the sauna, in the swimming pool, in the restaurant, in fact, practically anywhere. Some of them are uplink, others are downlink and some are bi-directional.
In addition to this, low customer satisfaction decreases the success of the operator. This is carried out in the surroundings of each individual site using portable test transmitters.
As an example, take a person who has a subscription for two basic services, Speech and Group 3 fax. To analyse the dialled digits. The following information is required when creating the subscriber: Handover due to measurements occurs when the quality or the strength of the radio signal falls below certain parameters specified in the BSC.
In a GSM network, this decentralised intelligence is implemented by dividing the whole network into three separate subsystems: This means that we must direct the call to it by using the following procedure: The other 6 bits are effectively wasted. Message Transfer Part layers The lowest level, MTP layer 1 physical connectionsdefines the physical and electrical characteristics.
Computer aided design systems and tools are used for coverage prediction, interference analysis, frequency planning, microwave link planning, documentation etc. After obtaining this value, we must take a look at the Erlang table. There is not enough information given for an exact answer. But who is the user who receives, sends and acts on these messages?
After the network has been dimensioned, a detailed plan is made with a number of inputs, for instance Data Communications Network DCN settings towards the NMS, network diagrams, the synchronisation plan, a detailed routing plan, digit analysis, detailed signalling, numbering and charging plans, etc.
Let us move on and take a closer look at the mobile network.
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