Since the policies from H-ANDSF and V-ANDSF in some cases may overlap, the UE needs to resolve any conflicts that may exist between the policies provided by the H-ANDSF and the policies provided by the V-ANDSF. The H-ANDSF provides mobility and routing policies that apply generally, while the V-ANDSF provides mobility and routing policies that will be valid only within the particular visited network. Slightly different principles apply for the mobility and routing policies. The H-ANDSF provides the UE with discovery information only for access networks that provide connectivity to the home network, while the V-ANDSF provides the UE with discovery information only for access networks that provide connectivity to the particular visited network. In Release 8 only the non-roaming architecture was specified but in Release 9 ANDSF has been extended with a roaming architecture, where a roaming UE can connect to both an ANDSF in the home network (H-ANDSF) and an ANDSF in the visited network (V-ANDSF), see Figure 6.28. The ANDSF Managed Object (MO) used with OMA-DM to carry the information between the UE and ANDSF is specified by 3GPP and is described in further detail in Chapter 15.
![tetrapol scc tetrapol scc](https://www.defenceweb.co.za/wp-content/uploads/industry/industry/400_MHz_PMR-300x160.jpg)
The ISMPs and ISRPs may be provided in the UE and can also be updated by the ANDSF based on network triggers or after receiving a request from a UE for network discovery and selection information. Figure 6.27 illustrates the content of this type of ISRP object.įor more details on the ANDSF MO, see the text on ANDSF-related interfaces in Chapter 15. The ISRPs for WLAN offload indicate what traffic shall or shall not be non-seamlessly offloaded to a WLAN. These rules contain the same type of information as the ISRPs for IP flow mobility but the purpose is different. This type of ISRP is used by a UE that uses the local IP address allocated in a WLAN network for traffic that does not need to traverse the EPC and a PDN GW. Overview of ISRP Object for IP Flow Mobility and for WLAN Offload. Figure 6.25 illustrates the content of the ISMP object.įigure 6.27. conditions indicating when a policy is valid (a time duration, a location area, etc.). Similar to the discovery information, the ISMPs also include validity conditions, i.e. WLAN SSID A is preferable to WLAN SSID B). The ISMPs can also indicate if a specific access network identifier is preferable to another (e.g. It may also indicate, for example, that WLAN access is preferable to WiMAX access.
![tetrapol scc tetrapol scc](https://www.jalux.com.ar/thumb/0GEN00000028840057056288400_800x800.jpg)
For example, an inter-system mobility policy may indicate that inter-system handover from E-UTRAN access to WiMAX access is not allowed. (When the UE is capable of using multiple radio interfaces at a time, the ISRPs are as described below.) The ISMPs may indicate when inter-system mobility is allowed or restricted, as well as the most preferable access technology type or access network that should be used to access EPC. The UE uses the inter-system mobility policy when it can use only a single radio access interface at a given time. Such access selection between 3GPP radio technologies is handled by other methods not related to ANDSF. The ISMPs do not contain policies that influence the choice of 3GPP access (e.g. decisions about whether to use 3GPP or non-3GPP access, and what type of non-3GPP access (e.g.
![tetrapol scc tetrapol scc](https://64.media.tumblr.com/8a5e3429e124a8d7e69e23c0fcc28eb5/4175900949e03db0-14/s400x600/3f0aa98bbea22a17d152f53088ca7ecea75814dd.gif)
The Inter-System Mobility Policies (ISMPs) are a set of operator-defined rules and preferences that affect the inter-system mobility decisions taken by the UE, i.e. The ANDSF may use this information to provide the UE with subscriber-specific network discovery and selection information that applies in the vicinity of the UE. The UE will, for example, provide its identity (IMSI) but may also provide its location (such as GPS coordinates or cell identities of nearby radio base stations), as well as information about what types of ANDSF information are requested by the UE. The UE may provide information to the ANDSF that assists the ANDSF when generating discovery and selection information. Furthermore, the detailed UE behavior when using info/policies received from ANDSF is mostly implementation dependent. ANDSF is thus not intended as a very dynamic access selection mechanism controlling access selection in real time. It should, however, be noted that ANDSF is (by design) not suitable for frequent/dynamic updates of policy.
![tetrapol scc tetrapol scc](https://docplayer.net/docs-images/48/23891034/images/page_16.jpg)
the UE can either request the information or the ANDSF can initiate the data transfer to the UE. The solution supports both “pull” and “push”, i.e.