GSM Location Update Precedure

The location update flow is as follows: - When a MS finds that better service is provided in a certain location area, this MS notifies the MSC of the MSC/VLR which this new location area belongs to.  - If the original location area and new location area belong to the same MSC/VLR, the MSC only changes the location information of this MS in the VLR. If the original location area and new location area belong to different MSCs/VLRs, the new...

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Electromagnetic Propagation Path

The electromagnetic propagation takes on an energy propagation mode. During the propagation, the electric field is vertical to the magnetic field, both vertical to the propagation direction. Through interaction between the electric field and the magnetic field, the energy is propagated to the distance,  just like propagation of water waves.  When the radio wave propagates in the air, the electric field direction changes regularly....

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The Signaling Process of MS Originated USSD Call

When the MS makes originate the USSD operation according to the input of the subscriber, the MS first sets up a connection to the network, and then sends a request to the MSC and waits for the response. Once the MS receives the response from the network side, the MS displays the information in the response message on its screen to the subscriber. During the waiting process, the MS may receive the USSD REQUEST or USSD NOTIFY message originated by...

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The Architecture of Signaling Number 7 (SS7)

From TUP, ISUP, and SCCP points of view, MTP is only a message transfer point that is used to transfer the messages of user parts to the user parts of destination signaling points. In brief, SS7 can be regarded as a TCP/IP network MTP Functions Message Transfer Part (MTP) provides services for transferring the messages of user parts (such as TUP, ISUP, and SCCP) to destinations through SS7. If SS7 experiences a fault, the messages can be transmitted...

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Basic Core Network Feature and Technologies

Core Network is devided into CS domain and PS domain. CS domain is based on original GSM network. PS domain is based on original GPRS network. CS domain is used to provide Circuit-switched service. Network mode can support TDM, ATM and IP. Physical entities include switching equipment (such as MSC/VLR, GMSCs), and inter-working equipment (IWF). PS domain is used to provide Packet-switched service. Network mode is IP. Physical entities include SGSN,...

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Characteristics of WCDMA FDD

The DS-CDMA system with a bandwidth of approximately 1MHz, i.e. IS-95, is generally named as narrowband CDMA system. But WCDMA owns a chip rate of 3.84Mcps, bringing approximately 5MHz carrier bandwidth.This feature enables the system to support higher bit rate, and at the same time brings other benefits, for example, increasing of multi-path diversity. Gold sequence is used as scrambling code in WCDMA In IS-95, only coherence detection...

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Basic Concept of Signaling SS7

Message Transfer Part (MTP) is mainly responsible for transmitting "User Part" signaling messages across the SS No. 7 network. If a system or signaling network is faulty, MTP can take measures to prevent messages from losing, and repeatedly or disorderly transmitting. MTP consists of signaling data links, signaling link functions, and signaling network functions. Here are the following exchange in SS7 Signaling point (SP): A signaling point...

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Multiple Access Technology

There are 3 types of multiple access technology 1.       Time division multiple access (TDMA) 2.       Frequency division multiple access (FDMA) 3.       Code division multiple access (CDMA) Time Division Multiple Access means that the wireless carrier of one bandwidth is divided into multiple time division channels in terms of time...

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GSM Location Update Flow

The procedure of location update is as follows: When a MS finds that better service is provided in a certain location area, this MS notifies the MSC of the MSC/VLR which this new location area belongs to. If the original location area and new location area belong to the same MSC/VLR, the MSC only changes the location information of this MS in the VLR. If the original location area and new location area belong to different MSCs/VLRs, the...

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