Network Reattachment via Cancel Location Signal
Solution Overview
Problem
Mobile devices often inadvertently connect to foreign networks near international or domestic borders, leading to unnecessary roaming charges and revenue loss for operators due to delayed re-registration with the home network.
Innovation Solution
A method involving a Cancel Location signal sent from the home network to the Visitor Location Register of a foreign network, allowing the mobile device to quickly reattach to the home network when coverage is available, using information from previous attachments and location comparisons to initiate the reattachment procedure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the mobile device performs periodic search for home network signal, then the device can maintain connection with current network, but the device may stay connected to foreign network for extended period resulting in unnecessary roaming charges
Solution Approach 1:
The home network proactively sends a Cancel Location signal to the foreign network's VLR before the mobile device would naturally trigger a network search. This preliminary action forces the device to reattach to the home network sooner, reducing unnecessary roaming duration while maintaining connection stability through controlled network management
Solution Approach 2:
The system implements feedback by monitoring when mobile devices attach to foreign networks and triggering Cancel Location signals based on this information. The foreign network's VLR receives location update requests from the home network, creating a feedback loop that enables dynamic control of roaming duration based on actual network conditions and device location
2Ease of operation
If the mobile device registers with foreign network when coverage is available, then service continuity is maintained, but roaming costs increase for both subscriber and operator
Solution Approach 1:
The home network sends Cancel Location signals proactively to prevent the mobile device from establishing prolonged connections with foreign networks. This preliminary intervention ensures that devices reattach to the home network before unnecessary roaming charges can accumulate, while still maintaining service continuity through controlled reattachment procedures
Solution Approach 2:
The VLR in the foreign network acts as an intermediary that receives Cancel Location signals from the home network. This intermediary mechanism enables the home network to control roaming behavior without directly interfering with the mobile device's connection management, allowing service continuity while reducing roaming costs through network-to-network coordination
3Adaptability or versatility
If the mobile device performs conventional network search, then the device can find available networks, but the search is periodic causing delayed re-registration with home network
Solution Approach 1:
Instead of waiting for periodic network searches, the home network performs preliminary action by sending Cancel Location signals to force immediate reattachment. This approach maintains network selection capability while dramatically improving re-registration speed by triggering the attachment process on-demand rather than waiting for periodic updates
Solution Approach 2:
The conventional approach has the mobile device actively searching for networks periodically. This invention inverts the approach by having the home network actively trigger reattachment through Cancel Location signals. This inversion transforms the slow, passive periodic search into a fast, active network-initiated reattachment process while preserving adaptability
Data Source
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AI summary
There is provided a method of initiating a network re - attachment procedure by a mobile device, the mobile device being attached to a network other than the home network of the mobile device, and wherein location information for the mobile device in said other network is stored in a visitor location register, VLR, in said other network, the method comprising transmitting a first signal between the home network and the mobile device, if the home network and/or the mobile device is aware that the mobile device is in a border cell of the visited network where there may or should be coverage from the home network. This first signal indicates that the network re - attachment procedure can be initiated, since it has been determined that the mobile device is in said border cell, the mobile device, when sending or receiving said first signal starts a timer. Subsequently, the home network transmits a second signal to the VLR of the visited network, which causes the location information relating to the mobile device to be deleted from the VLR. On expiry of a time period sufficient to allow the location imformation to be deleted from the VLR, the mobile device sends a service request to an MSC of the visited network and on rejection of the request to an MSC of the visited network and on rejection of the request (due to the fact that the mobile device is no longer known in the VLR), the mobile device initiates a network re - attachment (and hopefully registers with the home network).