[0033] In order to describe in detail the technical content, structural features, achieved objectives and effects of the present invention, the following will describe in detail in conjunction with embodiments and accompanying drawings.
[0034] As described in the background art, the prior art optimizes it in order to solve the problem of slow network search speed in the 3GPP standard. For example, for the public land mobile network PLMN that has been successfully registered, the mobile terminal will store it in the recently registered public land mobile network RRPLMN list in chronological order. The later the time, the higher the priority. Compared with the 3GPP standard, the search speed is indeed improved, but there is still a possibility of random selection, which increases the number of search attempts. The more attempts, the longer it will take to successfully register to the network. .
[0035] In view of the above technical shortcomings, based on the deep understanding of the industry technology and combined with years of work experience, the inventor creatively proposes a technical solution that can improve the existing technical shortcomings: that is, combined with positioning information, when the mobile terminal is successfully registered When it is a PLMN other than the home public land mobile network PLMN, it immediately records the geographic location information of the mobile terminal in the recently registered public land mobile network RRPLMN list. When a mobile terminal needs to use the recently registered public land mobile network RRPLMN list to perform a public land mobile network PLMN search, first calculate the current geographic location of the mobile terminal and the mobile terminal history recorded in the recently registered public land mobile network RRPLMN list. The distance between the geographic locations when successfully registering the public land mobile network PLMN, the shortest distance among these calculated distances corresponds to the public land mobile network PLMN that has been successfully registered with the highest priority, and it is ranked at the top of the list , And the shorter the distance, the higher the priority. According to the above scheme, since the randomness of the terminal movement is taken into consideration, it is definitely more reasonable than arranging the order in time. The order of searching the network is carried out according to the order of the public land mobile network PLMN list.
[0036] Combine below Figure 4 The technical scheme of the present invention is further explained in detail. Figure 4 It is a schematic flow chart of the method for quickly searching for a public land mobile network of the present invention.
[0037] When a mobile terminal enters a new public land mobile network PLMN area, it initiates a network search;
[0038] First try to register the registered public land mobile network RPLMN. If the registration is successful, the current geographic location information of the mobile terminal is obtained and stored in the recently registered public land mobile network RRPLMN list;
[0039] If the registration of the registered public land mobile network RPLMN fails, try to register the home public land mobile network HPLMN or the equivalent home public land mobile network EHPLMN. If the registration is successful, the current geographic location information of the mobile terminal is obtained and stored in Recently registered public land mobile network RRPLMN list;
[0040] If the registration of the home public land mobile network HPLMN or the equivalent home public land mobile network EHPLMN fails, try to register the user-controlled public land mobile network UPLMN or the operator-controlled public land mobile network OPLMN. If the registration is successful, obtain The current geographic location information of the mobile terminal is stored in the recently registered public land mobile network RRPLMN list;
[0041] If the home public land mobile network controlled by the registered user or the public land mobile network controlled by the operator fails, check whether the recently registered public land mobile network RRPLMN list is empty. If it is empty, randomly sort the remaining networks with signals. Try to register the network in order;
[0042] If the RRPLMN list of recently registered public land mobile network is not empty, then:
[0043] Obtain the location information of the current mobile terminal;
[0044] Calculate the distance between the current location of the mobile terminal and the geographical location recorded in the recently registered public land mobile network RRPLMN list;
[0045] Sort the public land mobile network PLMN in the recently registered public land mobile network RRPLMN list according to the calculated distance according to the smaller the distance, the higher the priority;
[0046] Try to register the network in the order of the public land mobile network PLMN in the recently registered public land mobile network RRPLMN list.
[0047] Register the network according to the above process. If the registration is successful, the mobile terminal successfully camps on the network, the search ends, and the location information is updated to the recently registered public land mobile network RRPLMN list. If the registration is unsuccessful, then randomly sort the remaining networks with signals; then try to register the networks in order. If the registration is successful, the mobile terminal successfully resides on the network, the search ends, and the location information is updated to the recently registered public Land mobile network RRPLMN list; if the registration is unsuccessful, the mobile terminal is in an emergency call state.
[0048] The current geographic location information of the mobile terminal obtained above can be expressed as (X, Y). The method of obtaining the geographic location information of the mobile terminal can be through systems such as GPS or Beidou satellite. At present, most mobile terminals have a positioning function.
[0049] The structure of the recently registered public land mobile network RRPLMN list is shown in Table 2, which is a two-dimensional storage structure. Each public land mobile network PLMN id records the geographic location information of the last N terminals that have successfully registered,
[0050] Table 2 RRPLMN list structure in the method of the present invention
[0051] PLMN id 1
[0052] If there are more than N pieces of information, the oldest geographic location information in time is deleted. Each geographic location information is represented by (Xpi, Ypi), and Xpi and Ypi respectively represent the longitude and latitude of the mobile terminal when the i-th successfully registered to the public land mobile network PLMN ID p. The maximum number of PLMN id is represented by M. The RRPLMN list can be saved on the SIM card or on the fixed memory of the mobile terminal itself.
[0053] The method of calculating the distance between the current location of the mobile terminal and the geographical location recorded in the list of recently registered public land mobile network RRPLMN can adopt formula 1. The mobile terminal will calculate all the previous registrations recorded in the list of recently registered public land mobile network RRPLMN The distance between the location corresponding to the successful public land mobile network PLMN and the current location of the mobile terminal is retained, and the shortest distance information is retained as the reference distance Dp of the network.
[0054] The specific distance calculation formula is: i=1~N, p=1~M (Formula 1)
[0055] Among them, X and Y respectively represent the longitude and latitude corresponding to the geographic location where the mobile terminal is currently located, and Xpi and Ypi respectively represent the longitude and latitude where the mobile terminal is located when the i-th successfully registered to the public land mobile network PLMN ID p. The values of N and M can be determined according to the size of the storage space and the performance of the mobile terminal itself. After all the distances are calculated, the priority of all networks is arranged according to the reference distance Dp. The smaller the Dp, the higher the priority of the public land mobile network PLMN. The mobile terminal tries to register on the public land mobile network PLMN according to this sequence. Once a certain network is successfully registered, it exits the trial process, and again updates the current location information of the mobile terminal to the recently registered public land mobile network RRPLMN list .
[0056] If all the public land mobile network PLMNs in the recently registered public land mobile network RRPLMN list cannot be successfully registered, then according to the requirements of 3GPP, try the remaining public land mobile network PLMN with better quality.
[0057] To sum up, the method for quickly searching public land mobile networks of the present invention utilizes the positioning function commonly available in smart phones, and uses the recently registered public land mobile network RRPLMN list to obtain and store the current mobile terminal location information, and then calculate the mobile The distance between the current location of the terminal and the geographical location recorded in the recently registered public land mobile network RRPLMN list, and according to the calculated distance, the smaller the distance, the higher the priority. The public land mobile network PLMN is sorted, and finally it tries to register the network in the order of the public land mobile network PLMN in the recently registered public land mobile network RRPLMN list. In the case that the mobile terminal leaves the home network, the time for successful registration on the new network is shortened as much as possible, and the possibility of the terminal being rejected by the network when registering on the network is also reduced to a certain extent. This has obvious benefits for improving user experience, saving terminal power, and maintaining the continuity of terminal services. It can be seen from the above description that the present invention improves the performance of mobile terminal search and registration from multiple aspects.
[0058] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention. , Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.
