Steering Control

The Steering Control is MTX Connect developed system that can be integrated with existing HLR/HSS and enables versatile visiting network subscribers' registration logic and control.

The goal of Steering Control is to ensure that subscribers only register in authorized networks according to existing active roaming agreements and defines priority logic for multiple roaming partners in particular region.

Two steering are supported:

• At the HLR/HSS registration level, access-lists (ACL) based. Supports ACL hierarchy, grouping and individual IMSI management.
• At the SIM OTA priority level, where specific OTA updates applied to PLNM files at the SIM profile. Can be integrated with existing OTA platform using standard SMS or HTTP based OTA.

To figure out what algorithm the platform will use, you'll need to know which ACL the given IMSI is assigned to and what PartID the given IMSI belongs to.

The PartID grouping sets the permission for OTA based steering updates.

In case the particular PartID restricts OTA updates (e.g. SIM profile doesn't have required re-writable PLNM files or OTA application), ACL–based algorithm is used.

The ACL algorithm to which the card is bound (and ACLs of higher levels, if any) is always applied for all cards.

In case the SIM profiles batch belongs to a PartID that allows OTA application, OTA based Steering Control can be enabled via dedicated OTA campaigns and can be flexibly tailored for each location.

• The country is in OTA Priority list, and all operators have similar access and services terms — all operators will be marked as preferred.
• The country is in OTA Priority list, but there is a preferred network partners to be used primarily by all outbound profiles — that network will be promoted to preferred status, while all other networks will be marked as neutral. Registration and operation will be available on any network in this case, but the SIM-card will receive an OTA SMS update and re-registration will prioritize the preferred network. All available networks in the ACL for this country must not be blocked.
• The country is in OTA Priority list, and there is a network that subscribers should never register to (no suitable access or services conditions). In this case the network should be marked as blocked at the ACL level and blocked at the OTA level. At the HLR/HSS level, any attempt to register will be blocked and SIM profile PLNM files will block this network for the user's device selection attempt.
• The country does not appear in OTA Priority lists (the check is based on ACL logic only) and has equivalent networks. All of the required ACLs will be set to high priority. Registration will be completed as soon as possible. In addition, where possible that SMS OTA will be sent pt the profile.
• The country is not in OTA Priority lists (the check is based on ACL logic), and the country's operators offer different service levels. For example, there is a partner with a higher price, but with better coverage.
  To address this issue, all necessary ACLs for the more expensive operators are set to medium or low priority. The difference between these two priority's is the amount of time that registration attempts are monitored. For instance, 3 registration attempts in 3 minutes for medium priority and 3 registration attempts in 1 hour for low priority, will be rejected at the HLR level, after which network registration will be re-allowed. The issue here could be that the VLR can cover a large area, and the SIM card may take a long time to register on the cheaper network.

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Following registration, the subscriber receives an OTA PLNM files update containing a list of forbidden and priority networks for the country in question, as well as neighboring countries.

It's worth noting that PLMNs are stored in the phone's memory in the order in which they arrive on the platform, so the network on the top of the list will have an advantage in registration.

The networks' order is random, and the database sampling is unsorted, with no guarantee of order.

Following generation, the list is cached for 15 minutes before being updated. The same list may be generated from time to time because the same algorithm is used.

The SIM will only try to register on the networks listed in the PTA during subsequent registrations, and will not try to register on any other networks until the PTA is updated. Registration attempts in other networks are only possible if there are coverage issues in the networks on the list. In this case, the re-registration command is not sent, and re-registration is not performed if the card received the OTA on the incorrect network.