Subject: Mobile Computing

Difficulty: Medium

Marks: 4 Marks

Attachment and Detachment Procedure:

• In order to access the GPRS services, anMSneeds to make its presence known to the network. It must register itself with an SGSN of the network.
• This is done through a GPRS attach. This operation establishes a logical link between the MS and the SGSN.
• The network checks if the MS is authorized to use the services; if so it copies the user profile from the HLR to the SGSN, and assigns a packets with external PDN after successful GPRS attach, a mobile station must apply for an address.
• This address called as PDN (packet data protocol) address. Allocation of the PDP address can be static or dynamic. In case static address the network operation permanently assigns a PDP address to the user. In dynamic allocation address change every time.

The disconnection from the GPRS Network is called GPRS Detach. All the resources are released following GPRS detach. Detach process can by initialized by the MS or by the network.