Controlled synchronization group selection

Abstract

Methods, apparatuses, and computer program products for synchronization in a network are provided. One method includes configuring a first node for joining a first timings synchronization group with a second node on a lowest stratum, receiving at least one synchronization signal comprising information on at least an identity of the second node, and synchronizing the first node to the first synchronization group based on the synchronization signal.

1 - 35 . (canceled) 
     
     
         36 . A method, comprising:
 searching for synchronization sources in a network;   determining a group with a highest preference that can be joined from a preference list; and   joining the determined group.   
     
     
         37 . The method according to  claim 36 , further comprising reporting the synchronization sources. 
     
     
         38 . The method according to  claim 36 , further comprising, when it is determined that none of the groups listed in the preference list can be joined, joining an unlisted group. 
     
     
         39 . The method according to  claim 36 , further comprising observing a synchronization conflict, and reporting the conflict to a network. 
     
     
         40 . The method according to  claim 36 , further comprising receiving an updated preference list for synchronization. 
     
     
         41 . The method according to  claim 36 , wherein the preference list comprises synchronization sources on several preference levels. 
     
     
         42 . The method according to  claim 36 , wherein the preference list comprises multiple, mutually synchronized sources on a same preference level. 
     
     
         43 . The method according to  claim 36 , further comprising receiving a stratum information from at least one of the synchronization sources. 
     
     
         44 . The method according to  claim 43 , wherein the stratum information is a broadcast information. 
     
     
         45 . The method according to  claim 43 , wherein the stratum information is carried in a physical broadcast channel or a physical downlink shared channel resources. 
     
     
         46 . An apparatus, comprising:
 at least one processor; and   at least one memory including computer program code,   wherein the at least one memory and the computer program code are configured, with the at least one processor, to cause the apparatus at least to   search for synchronization sources in a network;   determine a group with a highest preference that can be joined from a preference list; and   join the determined group.   
     
     
         47 . The apparatus according to  claim 46 , wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to report the synchronization sources. 
     
     
         48 . The apparatus according to  claim 46 , wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to, when it is determined that none of the groups listed in the preference list can be joined, join an unlisted group. 
     
     
         49 . The apparatus according to  claim 46 , wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to observe a synchronization conflict, and report the conflict to a network. 
     
     
         50 . The apparatus according to  claim 46 , wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to receive an updated preference list for synchronization. 
     
     
         51 . The apparatus according to  claim 46 , wherein the preference list comprises synchronization sources on several preference levels. 
     
     
         52 . The apparatus according to  claim 46 , wherein the preference list comprises multiple, mutually synchronized sources on a same preference level. 
     
     
         53 . The apparatus according to  claim 46 , wherein the apparatus comprises at least one of a user equipment, a base station, an evolved node B, or an access point. 
     
     
         54 . The apparatus according to  claim 46 , wherein the at least one memory and the computer program code are further configured, with the at least one processor, to cause the apparatus at least to receive a stratum information from at least one of the synchronization sources. 
     
     
         55 . The apparatus according to  claim 54 , wherein the stratum information is a broadcast information. 
     
     
         56 . The apparatus according to  claim 54 , wherein the stratum information is carried in a physical broadcast channel or a physical downlink shared channel resources. 
     
     
         57 . A computer program, embodied on a computer readable medium, the computer program configured to control a processor to perform a process, comprising:
 searching for synchronization sources in a network;   determining a group with a highest preference that can be joined from a preference list; and   joining the determined group.