Abstract:
Methods and apparatus related to peer, network or service discovery in a mobile wireless system, such as an ad hoc peer-to-peer network, are described. Transmission of discovery information, such as upper layer discovery information, is divided into a number of portions to be transmitted separately over time. Transmission of the individual portions is structured to enable flexibility in the frequency of the peer discovery transmissions as well as the monitoring of such transmissions. Various embodiments facilitate rapid discovery and secure discovery, such as selective discovery by trusted peers. The structuring enables proxying of some transmissions by a third party, such as an assist node. The assist node receives discovery information portions being communicated at a first rate and retransmits the received discovery information portions at a second rate which is higher than the first rate.

Description:
FIELD 
     Various embodiments relate to wireless communications, and more particularly, to methods and apparatus related to the communication of peer discovery information. 
     BACKGROUND 
     In a wireless network, e.g., an ad hoc peer to peer wireless network, it can be beneficial for a wireless communications device, e.g., a mobile node, to support the ability to transmit, e.g., broadcast, various types of discovery information, e.g., peer discovery information, network discovery information and/or service discovery information. The broadcasting of such information can be used by other peer devices currently in its local vicinity to form a situational awareness. This exchange of wireless device broadcast discovery information among peers can be particularly useful in a network lacking centralized coordination and/or control. Different wireless communications devices may have different capabilities and/or needs with regard to the transmission and/or reception of discovery information. In addition, an individual wireless communications device may, at different times, have different capabilities and/or needs with regard to the transmission and/or reception of discovery information. Broadcasting discovery information may be considered overhead signaling, and resources such as power expended for discovery information signaling transmissions may be unavailable for traffic signaling. The power expended by a mobile wireless communications device for transmitting discovery information and the reserve battery power remaining are important considerations in implementing a structure supporting the communication of discovery information. The transmitting of discovery information at a high rate has the benefit of reducing discovery latency, yet comes at a cost of expending more power, e.g., reducing battery lifetime. 
     Based on the above discussion it should be appreciated there is a need for novel methods and apparatus that support rapid communication of discovery information, yet do not overly tax the limited power resources of battery operated mobile devices. 
     SUMMARY 
     Various embodiments relate to wireless communications systems which enables direct wireless communications between subscriber devices, e.g., ad hoc peer to peer networks including mobile devices. In accordance with a feature of some embodiments, a process known as peer discovery enables autonomous detection of peers, networks, and/or services that are of interest to a particular subscriber device. In some instances, the implemented peer discovery mechanisms support multiple rates of sending and/or monitoring peer discovery information. Thus at a given location and time, some subscriber devices may be performing peer discovery at a first rate, e.g., a low rate, while other devices may be performing peer discovery at a second rate, e.g., a high rate. In general performing peer discovery operations at a higher rate has the benefit of reducing latency at the cost of utilizing more communication resources and expending more power, e.g., reducing battery lifetime. 
     To enable the benefits of high rate discovery, e.g., reduced discovery latency, without incurring the cost of expending more power on a battery powered device, e.g., reducing battery life of a mobile wireless device, a peer discovery assist capable node is utilized. The peer discovery assist node receives low rate peer discovery information from one or more other nodes and resends substantially equivalent information at a higher rate. In various embodiments, peer discovery information is structured so as to allow this behavior while still maintaining desired feature functionality, e.g., security. In some embodiments, a peer discovery assist node is a device with abundant power, e.g., having a hard wired power source. In some embodiments, a peer discovery assist node may, and sometimes does, assist operations for a plurality of other nodes. In some other instances, any node in the system can provide peer discovery assistance to any other node in the system, e.g., as determined by a variety of policy and performance constraints. 
     Methods and apparatus related to peer/network/service discovery in a mobile wireless system, e.g., an ad hoc peer-to-peer network are described. Transmission of discovery information, e.g., upper layer discovery information, is divided into a number of portions to be transmitted separately over time. Transmission of the individual portions is structured so as to enable flexibility in the frequency of the peer discovery transmissions as well as the monitoring of such transmissions. 
     Some air link resources, e.g., discovery information segments, are associated with low rate discovery signaling, while other air link resources are associated with high rate discovery information signaling. A signal communicated on an additional air link resource associated with high rate discovery signaling conveys a discovery information portion previously transmitted on a low rate discovery signal air link resource. Various embodiments facilitate rapid discovery and/or secure discovery, e.g., selective discovery by trusted peers. 
     The structuring enables proxying of some transmissions by a third party, e.g., a first node functioning to provide discovery assistance for other nodes. The first node is, e.g., an assist node, a server node such as a base station, or a wireless terminal such as a mobile node. For example, second device, e.g., a peer to peer wireless device in an ad hoc wireless network, which is currently operating in a low rate discovery transmit mode, is transmitting discovery information at a low rate using low rate discovery air link resources. A first node which is functioning to assist in discovery, located in the vicinity of the second node and which has decided to assist the second device, receives the low rate discovery signals from the second device and retransmits the received low rate discovery signals during additional high rate discovery intervals. Thus the first node discovery transmissions supplement the second node discovery transmissions. A third node, e.g., another peer to peer communications device in the vicinity, is able to receive low rate discovery signals from the second node and high rate discovery signals from the first node. Thus the third node is able to recover discovery information as if the second communications device had been in high rate discovery mode and had transmitted each of the discovery signals. In various embodiments, the proxying is performed by the first node without comprising the overall security of the discovery process. 
     An exemplary method of operating a first node, e.g., an assist node, a server node such as a base station, or a wireless terminal, to assist in communicating peer discovery information corresponding to a second node comprises: receiving over an airlink portions of one or more sets of peer discovery information from the second node, said portions being received at a first rate; and transmitting over an airlink at a second rate which is faster than said first rate, received portions of peer discovery information corresponding to said first node. An exemplary first node to assist in communicating peer discovery information corresponding to a second node comprises: a wireless receiver module for receiving over an airlink portions of one or more sets of peer discovery information from the second node, said portions being received at a first rate and a wireless transmitter module for transmitting over an airlink at a second rate which is faster than said first rate, received recovered portions of peer discovery information corresponding to said first node. In some embodiments, the first node further comprises one or more of: a peer discovery portion recovery module for recovering said received portions; a storage module for storing said recovered received portions. In various embodiments, the first node further comprises: an assist control module for controlling said wireless transmitter module to transmit said received recovered portion of peer discovery information corresponding to the second node at the second rate. In some embodiments, the first node supports discovery node assistance for multiple nodes operating in low rate discovery transmit mode. 
     While various embodiments have been discussed in the summary above, it should be appreciated that not necessarily all embodiments include the same features and some of the features described above are not necessary but can be desirable in some embodiments. Numerous additional features, embodiments and benefits of various embodiments are discussed in the detailed description which follows. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a drawing of an exemplary peer to peer network in accordance with an exemplary embodiment. 
         FIG. 2  illustrates discovery intervals and corresponding discovery interval air link resources within a recurring peer to peer timing structure in accordance with an exemplary embodiment. 
         FIG. 3  illustrates a more detailed representation of a first exemplary discovery interval&#39;s air link resources. 
         FIG. 4  illustrates a more detailed representation of a second exemplary discovery interval&#39;s air link resources. 
         FIG. 5  illustrates a plurality of ordered transmission units available for transmitting discovery information corresponding to a device identifier which are part of a peer discovery transmission structure. 
         FIG. 6  illustrates a securing hash function encoding module processing input discovery information to generate encoded information. 
         FIG. 7  illustrates a securing hash function encoding module processing some input discovery information, e.g., discovery identification information, which generates secure encoded information. 
         FIG. 8  illustrates 3 exemplary formats for discovery information being conveyed using four output portions corresponding to input discovery information. 
         FIG. 9  illustrates mapping of generated portions to ordered transmission units for conveying discovery information associated with a device identifier in accordance with one exemplary embodiment. 
         FIG. 10  illustrates mapping of generated portions to ordered transmission units for conveying discovery information associated with a device identifier in accordance with another exemplary embodiment. 
         FIG. 11  is a flowchart of an exemplary method of operating a first node to assist in communicating peer discovery information corresponding to a second node. 
         FIG. 12 , comprising the combination of  FIG. 12A  and  FIG. 12B , is a flowchart of an exemplary method of operating a node, e.g., an assist node or a server node such as a base station, to assist in communicating discovery information. 
         FIG. 13  is a drawing of an exemplary communications node, e.g., a peer discovery assist node or server node such as a base station node, in accordance with an exemplary embodiment. 
         FIG. 14  is a drawing illustrating exemplary nodes in a peer to peer communications system and the transmission of discovery information. 
         FIG. 15  is a drawing illustrating an exemplary peer to peer wireless terminal, an exemplary assist node, air link resources associated with communicating discovery information portions, and exemplary signaling in accordance with one exemplary embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a drawing of an exemplary peer to peer network  100  in accordance with an exemplary embodiment. Peer to peer network  100  includes a plurality of wireless peer to peer communications devices (peer to peer communications device  1   102 , peer to peer communications device  2   104 , peer to peer communications device  3   106 , peer to peer communications device  4   108 , . . . , peer to peer communications device N  110 ). Some of the peer to peer communications devices, e.g., peer to peer communications device  4   108 , also include a wired interface which couples the device to other nodes and/or the Internet. The peer to peer communications devices ( 102 ,  104 ,  106 ,  108 ,  110 ) store information defining a peer discovery transmission structure including transmission units to be used for low rate discovery transmissions and additional transmission units to be used for high rate discovery transmissions. 
     Peer to peer network  100  also includes a peer discovery assist node  114 , a server node  112 , e.g., a base station, and a beacon transmitter  116 . Peer discovery assist node  114  can, and sometimes does, receives portions of one or more sets of peer discovery information from one or more peer to peer communications devices at a first rate and transmits the information over an airlink at a second rate which is faster than the first rate. Similarly, server node  112  can, and sometimes does, receives portions of one or more sets of peer discovery information from a peer to peer communications device at a first rate and transmits the information over an airlink at a second rate which is faster than the first rate. Server node  112  includes both a wireless interface and a wired interface. The wired interface of the server  112  couples the server to other network nodes and/or the Internet. Beacon transmitter  116  transmits a beacon signal, e.g., an OFDM beacon signal having a high power concentration on one or a few tones, which is easily detectable and intended to be utilized by the peer to peer devices in its vicinity to establish a timing reference with respect to the peer to peer timing structure being utilized in the region. 
       FIG. 2  includes a drawing  200  illustrating discovery intervals (discovery interval  1   214 , discovery interval  2   216 , . . . , discovery interval n  218 ) within a recurring peer to peer timing structure including an ultra slot  212 . In the recurring peer to peer timing structure the ultra slot repeats. Vertical axis  202  represents frequency, e.g., OFDM tones, while horizontal axis  204  represents time. Corresponding to each of discovery intervals (discovery interval  1   214 , discovery interval  2   216 , . . . , discovery interval n  218 ) there is a corresponding block of discovery interval air link resources (discovery interval  1  air link resources  206 , discovery interval  2  air link resources  208 , . . . discovery interval n air link resources  210 ). Each block of discovery interval air link resources, e.g., discovery interval  1  air link resources  206 , is, e.g., a block of OFDM tone-symbols, where each OFDM tone-symbol represents one OFDM tone for the duration of one OFDM symbol transmission time interval. 
       FIG. 3  shows a more detailed representation of discovery interval  1  air link resources  206  in accordance with one exemplary embodiment. Discovery interval  1  air link resources  206  include a plurality of discovery air link resources corresponding to different device identifiers. Discovery interval  1  air link resources includes device ID  1  discovery resource  302 , followed by device ID  2  discovery resource  304 , followed by device ID  3  discovery resource  306 , followed by device ID  4  discovery resource  308 , followed by device ID  5  discovery resource  310 , followed by device ID  6  discovery resource  312 , followed by device ID  7  discovery resource  314 , . . . , and device ID M discovery resource  316 . 
       FIG. 4  shows a more detailed representation of discovery interval  2  air link resources  208  in accordance with one exemplary embodiment. Discovery interval  2  air link resources  208  include a plurality of discovery air link resources corresponding to different device identifiers. Discovery interval  2  air link resources  208  includes device ID  3  discovery resource  402 , followed by device ID  5  discovery resource  404 , followed by device ID  4  discovery resource  406 , followed by device ID M discovery resource  408 , followed by device ID  2  discovery resource  410 , followed by device ID  6  discovery resource  412 , followed by device ID  1  discovery resource  414 , . . . , and device ID  7  discovery resource  416 . It may be observed that the order of the discovery resources associated with different device identifiers has changed from discovery interval  1   206  to discovery interval  2   208  in this exemplary embodiment. The ordered change in accordance with a predetermined hopping sequence employed in the peer to peer timing/frequency structure being utilized. In some other embodiments, the relative position of air link resources associated with a particular device identifier does not change from one interval to the next. 
       FIG. 5  is a drawing  500  illustrating a plurality of ordered transmission units available for transmitting discovery information which are part of a peer discovery transmission structure. The plurality of illustrated ordered transmission units include transmission unit  0   502 , transmission unit  1   504 , transmission unit  2   506 , transmission unit  3   508 , transmission unit  4   510 , transmission unit  5   512 , transmission unit  6   514 , transmission unit  7   516 , transmission unit  8   518 , transmission unit  9   520 , transmission unit  10   522 , transmission unit  11   524 , transmission unit  12   526 , transmission unit  13   528 , transmission unit  14   530 , transmission unit  15   532 , transmission unit  16   534 , transmission unit  17   536 , transmission unit  18   538  and transmission unit  19   540 , which are part of a peer discovery transmission structure, and which are associated with a particular device identifier. For example, consider that the transmission units in drawing  500  of  FIG. 5  belong to device ID  2 . Continuing with the example, transmission unit  0   502  may be device ID  2  discovery resource  304  of discovery interval  1  air link resources  206  and transmission unit  1   504  may be device ID  2  discovery resource  410  of discovery interval  2  of air link resources  208 , as illustrated in  FIGS. 2 ,  3  and  4 . 
     The plurality of ordered transmission units available for transmitting peer discovery information includes low rate discovery transmission units corresponding to a device identifier as indicated by grouping  542  and additional transmission units to be used for high rate discovery corresponding to the same device identifier as indicated by grouping  544 . In this example, the set of low rate discovery transmission units corresponding to the device identifier  542  are illustrated with crosshatch shading and include transmission units  502 ,  512 ,  522  and  532 . The set of additional transmission units to be used for high rate discovery corresponding to the device identifier are illustrated without shading and include transmission units  504 ,  506 ,  508 ,  510 ,  514 ,  516 ,  518 ,  520 ,  524 ,  526 ,  528 ,  530 ,  534 ,  536 ,  538  and  540 . 
       FIG. 6  illustrates a securing hash function encoding module  604  processing input discovery information which generates encoded information. The output encoded information is mapped to portions, each portion being communicated via a transmission unit. 
     Drawing  600  illustrates that the secure hash function encoding module  604  receives discovery information  602  and time value t 0   606  and generates a set of output information including a plurality of portions (A N-2 , B N-2 , C N-2 , D N-2 ) as indicated by column  608 . In this example, each portion corresponds to 16 information bits as indicated by column  610 . Column  612  indicates that there is a correspondence between different encoded output portions and transmission unit types. More particularly, portion A N-2  is to be communicated using a P0 transmission unit type in the recurring timing structure; portion B N-2  is to be communicated using a P1 transmission unit type in the recurring timing structure; portion C N-2 , is to be communicated using a P2 transmission unit type in the recurring timing structure; and portion D N-2 , is to be communicated using a P3 transmission unit type in the recurring timing structure. 
     Drawing  630  illustrates that the secure hash function encoding module  604  receives discovery information  632  and time value t 1   636  and generates a set of output information including a plurality of portions (A N-1 , B N-1 , C N-1 , D N-1 ) as indicated by column  638 . In this example, each portion corresponds to 16 information bits as indicated by column  640 . Column  642  indicates that there is a correspondence between different encoded output portions and transmission unit types. More particularly, portion A N-1  is to be communicated using a P0 transmission unit type in the recurring timing structure; portion B N-1  is to be communicated using a P1 transmission unit type in the recurring timing structure; portion C N-1 , is to be communicated using a P2 transmission unit type in the recurring timing structure; and portion D N-1 , is to be communicated using a P3 transmission unit type in the recurring timing structure. 
     Drawing  650  illustrates that the secure hash function encoding module  604  receives discovery information  652  and time value t 2   656  and generates a set of output information including a plurality of portions (A N , B N , C N , D N ) as indicated by column  658 . In this example, each portion corresponds to 16 information bits as indicated by column  660 . Column  662  indicates that there is a correspondence between different encoded output portions and transmission unit types. More particularly, portion A N  is to be communicated using a P0 transmission unit type in the recurring timing structure; portion B N  is to be communicated using a P1 transmission unit type in the recurring timing structure; portion C N , is to be communicated using a P2 transmission unit type in the recurring timing structure; and portion D N  is to be communicated using a P3 transmission unit type in the recurring timing structure. 
     Input discovery information  602  may be the same or different from input discovery information  632 . Similarly, input discovery information  632  may be the same or different from input discovery information  652 . In each case, the secure hashing function encoding module  604 , may, and in some instances does, include additional inputs, e.g., a key, as needed for operation. 
       FIG. 7  illustrates a securing hash function encoding module  704  processing some input discovery information, e.g. discovery identification information, which generates secure encoded information. The output secure encoded information is combined by combining module  703  with additional discovery information, e.g., bits representing type information and/or flags. The result of the combination is mapped to portions, each portion being communicated via a transmission unit. 
       FIG. 7  thus illustrates a variation on the exemplary embodiment shown in  FIG. 6 . In the example of  FIG. 7  some discovery information which is communicated is not subjected to secure hash function encoding. For example, bits representing type information and/or bits representing flags may be, and sometimes are, not subjected to secure hash function encoding. In the example of  FIG. 7 , discovery information ( 702 ,  732 ,  752 ) includes discovery information ( 702   a ,  732   a ,  752   a ), respectively, which is subjected to secure hash function encoding and discovery information ( 702   b ,  732   b ,  752   b ), respectively, which is not subjected to secure hash function encoding. 
     Drawing  700  illustrates that the secure hash function encoding module  704  receives discovery information  702   a  and time value t 0   706  and generates secure encoded information  705 . Combining module  703  receives secure encoded information  705  and discovery information  702   b  and generates a set of output information including a plurality of portions (A N-2 , B N-2 , C N-2 , D N-2 ) as indicated by column  708 . In this example, each portion corresponds to 20 information bits as indicated by column  710 . Column  712  indicates that there is a correspondence between different encoded output portions and transmission unit types. More particularly, portion A N-2  is to be communicated using a P0 transmission unit type in the recurring timing structure; portion B N-2  is to be communicated using a P1 transmission unit type in the recurring timing structure; portion C N-2 , is to be communicated using a P2 transmission unit type in the recurring timing structure; and portion D N-2 , is to be communicated using a P3 transmission unit type in the recurring timing structure. 
     Drawing  730  illustrates that the secure hash function encoding module  704  receives discovery information  732   a  and time value t 1   736  and generates secure encoded information  735 . Combining module  703  receives secure encoded information  735  and discovery information  732   b  and generates a set of output information including a plurality of portions (A N-1 , B N-1 , C N-1 , D N-1 ) as indicated by column  738 . In this example, each portion corresponds to 20 information bits as indicated by column  740 . Column  742  indicates that there is a correspondence between different encoded output portions and transmission unit types. More particularly, portion A N-1  is to be communicated using a P0 transmission unit type in the recurring timing structure; portion B N-1  is to be communicated using a P1 transmission unit type in the recurring timing structure; portion C N-1 , is to be communicated using a P2 transmission unit type in the recurring timing structure; and portion D N-1 , is to be communicated using a P3 transmission unit type in the recurring timing structure. 
     Drawing  750  illustrates that the secure hash function encoding module  704  receives discovery information  752   a  and time value t 2   756  and generates secure encoded information  755 . Combining module  703  receives secure encoded information  755  and discovery information  752   b  and generates a set of output information including a plurality of portions (A N , B N , C N , D N ) as indicated by column  758 . In this example, each portion corresponds to 20 information bits as indicated by column  760 . Column  762  indicates that there is a correspondence between different encoded output portions and transmission unit types. More particularly, portion A N  is to be communicated using a P0 transmission unit type in the recurring timing structure; portion B N  is to be communicated using a P1 transmission unit type in the recurring timing structure; portion C N , is to be communicated using a P2 transmission unit type in the recurring timing structure; and portion D N , is to be communicated using a P3 transmission unit type in the recurring timing structure. 
     Input discovery information  702  may be the same or different from input discovery information  732 . Similarly, input discovery information  732  may be the same or different from input discovery information  752 . In each case, the secure hashing function encoding module  704  may, and in some instances does, include additional inputs, e.g., a key, as needed for operation. 
       FIG. 8  illustrates 3 exemplary formats for discovery information being conveyed using four output portions. Drawing  800  illustrates a first exemplary format in which output discovery identification information  802  to be transmitted includes 64 bits as indicated by block  804  and includes 4 portions (portion A  806 , portion B  808 , portion C  810 , and portion D  812 . This format is an exemplary format corresponding to the examples of  FIG. 6 . For example, the four output portions (portion A  806 , portion B  808 , portion C  810 , portion D  812 ) of drawing  800  of  FIG. 8  are the set of {A n-2 , B n-2 , C n-2  and D n-2 }, or the set of four output portions are {A n-1 , B n-1 , C n-1  and D n-1 }, or the set {A n , B n , C n  and D n } of  FIG. 6 . 
     Drawing  820  illustrates a second exemplary format in which output discovery identification information  834  to be transmitted includes 80 bits and includes 4 output portions (portion A  834 , portion B  836 , portion C  838 , and portion D  840 ). This format is an exemplary format corresponding to the examples of  FIG. 7 . For example, the four output portions (portion A  834 , portion B  836 , portion C  840 , portion D  842 ) of drawing  820  of  FIG. 8  are the set of {A n-2 , B n-2 , C n-2  and D n-2 }, or the set of four output portions are {A n-1 , B n-1 , C n-1  and D n-1 }, or the set {A n , B n , C n  and D n  } of  FIG. 7 . In example of drawing  820 , the output discovery information to be communicated includes a type field  822  which is 8 bits wide as indicated by  828  and a flags field  824  which is 8 bits wide as indicated by block  830  and a discovery identification information field  826  which is 64 bits wide as indicated by block  832 . In the example of drawing  820  the type field  822  and the flags field  824  are included as part of portion A  834 , while the discovery identification information  826  is communicated using bits in portion A  834 , portion B  836 , portion C  838  and portion D  840 . 
     Drawing  850  illustrates a third exemplary format in which output discovery identification information  834  to be transmitted includes 80 bits and includes 4 output portions (portion A  893 , portion B  895 , portion C  897 , and portion D  899 ). This format is an exemplary format corresponding to the examples of  FIG. 7 . For example, the four output portions (portion A  893 , portion B  895 , portion C  897 , portion D  899 ) of drawing  850  of  FIG. 8  are the set of {A n-2 , B n-2 , C n-2  and D n-2 }, or the set of four output portions are {A n-1 , B n-1 , C n-1  and D n-1 }, or the set {A n , B n , C n  and D n } of  FIG. 7 . In the example of drawing  850 , the discovery information to be communicated in portion A  893  includes a type field  852  which is 2 bits wide as indicated by block  876 , a flags field  854  which is 2 bits wide as indicated by block  878  and a discovery identification information field  856  which is 16 bits wide as indicated by block  880 . The discovery information to be communicated in portion B  895  includes a type field  858  which is 2 bits wide as indicated by block  882 , a flags field  860  which is 2 bits wide as indicated by block  884  and a discovery identification information field  862  which is 16 bits wide as indicated by block  886 . The discovery information to be communicated in portion C  897  includes a type field  864  which is 2 bits wide as indicated by block  888 , a flags field  866  which is 2 bits wide as indicated by block  890  and a discovery identification information field  868  which is 16 bits wide as indicated by block  892 . The discovery information to be communicated in portion D  899  includes a type field  870  which is 2 bits wide as indicated by  894 , a flags field  872  which is 2 bits wide as indicated by block  896  and a discovery identification information field  874  which is 16 bits wide as indicated by block  898 . 
     Type information conveyed in a type field includes, e.g., information indicating a format of other discovery information being conveyed, e.g., other upper layer discovery information. For example, a type value conveyed in the type field is used to identify how to process the discovery information being conveyed, e.g., different type values map to different formats which can be used and/or different encoding which can be used and/or different encryptions which can be used. Type field information can be, and sometimes is, used to convey what the contents of processed, e.g., hashed, discovery information represents. 
     Flags are used to indicate one or more binary conditions, e.g., capabilities or features. In some embodiments, flags are used to identify a device type, e.g., a router. In some embodiments, a portion of the discovery information to be conveyed is included in every transmission portion. In some embodiments, a portion of the discovery information to be conveyed is split over a set of associated peer discovery transmission portions. Some portions of discovery information, e.g. a subset of flags may be sufficiently time critical to include in every transmission portion. In some embodiments, to be able to interpret some discovery information being communicated, a receiving device needs to have already received a type value; thus in such an embodiment, the frequency at which Type is conveyed can, and sometimes does, impact the ability to react to partial sets of discovery information. In some such embodiments, a type field is included in each discovery transmission portion to facilitate rapid recovery of discovery information being conveyed in a received transmitted portion. 
     Other embodiments, may include other fields in addition to or in place of those described with respect to  FIG. 8 , e.g., a header field, a CRC field, etc. 
       FIG. 9  illustrates mapping of the generated portions of  FIG. 6  or  FIG. 7  to ordered transmission units for conveying discovery information associated with a wireless communications device identifier in accordance with one exemplary embodiment using a particular mapping pattern. An ordered sequence of transmission units ( 904 ,  906 ,  908 ,  910 ,  912 ,  914 ,  916 ,  918 ,  920 ,  922 ,  924 ,  926 ,  928 ,  930 ,  932 ,  934 ,  936 ,  938 ,  940 ,  942 ,  944 ,  946 ,  948 ,  950 ,  952 ,  954 ,  956 ,  958 ,  960 ,  962 ,  964 ,  966 ,  968 ,  970 ,  972 ,  974 ,  976 ,  978 ,  980 ,  982 ) which are of the type (P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3), respectively, and which convey information (A N-1 , B N-2 , C N-2 , D N-2 , A N-1 , B N-1 , C N-2 , D N-2 , A N-1 , B N-1 , C N-1 , D N-2 , A N-1 , B N-1 , C N-1 , D N-1 , A N-1 , B N-1 , C N-1 , D N-1 , A N , B N-1 , C N-1 , D N-1 , A N , B N , C N-1 , D N-1 , A N , B N , C N , D N-1 , A N , B N , C N , D N , A N , B N , C N , D N ), respectively. It may be observed that transmission units ( 904 ,  914 ,  924 ,  934 ,  944 ,  954 ,  964 , and  974 ) are low rate discovery transmission units as indicated by crosshatch shading, while transmission units ( 906 ,  908 ,  910 ,  912 ,  916 ,  918 ,  920 ,  922 ,  926 ,  928 ,  930 ,  932 ,  936 ,  938 ,  940 ,  942 ,  946 ,  948 ,  950 ,  952 ,  956 ,  958 ,  960 ,  962 ,  966 ,  968 ,  970 ,  972 ,  976 ,  978 ,  980  and  982 ) are additional transmission units to be used for high rate discovery. It should be noted, that an additional transmission unit for high rate discovery of a given type is designated to carry the information portion that has been previously transmitted via a low rate discovery transmission unit of the same type, when it carries a transmission unit. 
     If a first peer to peer communications device having the identifier corresponding to the set of transmission units is in high rate discovery information transmit mode, it transmits using each of the transmission units. However, if first the peer to peer communications device is in low rate discovery transmit mode it transmits using the low rate discovery resources, but refrains from transmitting on the additional transmission resources designated for high rate discovery. The structure of  FIG. 9  illustrates the dissemination of the same portions of discovery information from a first peer to peer communications irrespective of the transmit mode, but facilitates a more rapid potential recovery of the information by a second peer to peer device if high rate mode is used. In addition, this illustrated structure of  FIG. 9  advantageously facilitates a peer discovery assist node or base station being able to: (i) receive and detect discovery signals being communicated from a first peer to peer communications device transmitting discovery signals using low discovery rate transmission units but not additional transmission units designated for high discovery rate, and (ii) then broadcast such received information using the additional transmission units designated for high rate discovery, e.g., filling in the otherwise unused additional transmission units designated for high rate discovery. A second peer to peer communications device attempting to detect peer discovery information from the first peer discovery device can receive and process discovery transmission units which occur on each of the transmission units associated with the device identifier. The second peer to peer communications device need not know the transmission source of a particular additional transmission unit signal, e.g., the first communications device or the assist node. 
       FIG. 10  illustrates mapping of the generated portions of  FIG. 6  or  FIG. 7  to ordered transmission units for conveying discovery information associated with a wireless communications device identifier in accordance with another exemplary embodiment. An ordered sequence of transmission units ( 1004 ,  1006 ,  1008 ,  1010 ,  1012 ,  1014 ,  1016 ,  1018 ,  1020 ,  1022 ,  1024 ,  1026 ,  1028 ,  1030 ,  1032 ,  1034 ,  1036 ,  1038 ,  1040 ,  1042 ,  1044 ,  1046 ,  1048 ,  1050 ,  1052 ,  1054 ,  1056 ,  1058 ,  1060 ,  1062 ,  1064 ,  1066 ,  1068 ,  1070 ,  1072 ,  1074 ,  1076 ,  1078 ,  1080 ,  1082 ) which are of the type (P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3, P0, P1, P2, P3), respectively, and which convey information (A N-1 , B N-2 , C N-2 , D N-2 , A N-2 , B N-1 , C N-2 , D N-2 , A N-2 , B N-2 , C N-1 , D N-2 , A N-2 , B N-2 , C N-2 , D N-1 , A N-1 , B N-1 , C N-1 , D N-1 , A N , B N-1 , C N-1 , D N-1 , A N-1 , B N , C N-1 , D N-1 , A N-1 , B N-1 , C N , D N-1 , A N-1 , B N-1 , C N-1 , D N , A N , B N , C N , D N ), respectively. It may be observed that transmission units ( 1004 ,  1014 ,  1024 ,  1034 ,  1044 ,  1054 ,  1064 , and  1074 ) are low rate discovery transmission units as indicated by crosshatch shading, while transmission units ( 1006 ,  1008 ,  1010 ,  1012 ,  1016 ,  1018 ,  1020 ,  1022 ,  1026 ,  1028 ,  1030 ,  1032 ,  1036 ,  1038 ,  1040 ,  1042 ,  1046 ,  1048 ,  1050 ,  1052 ,  1056 ,  1058 ,  1060 ,  1062 ,  1066 ,  1068 ,  1070 ,  1072 ,  1076 ,  1078 ,  1080  and  1082 ) are additional transmission units to be used for high rate discovery. It should be noted, that an additional transmission unit for high rate discovery is designated to carry an information portion that has been previously transmitted via a low rate discovery transmission unit, when it carries a transmission unit. In this example, the information carried on the additional resources associated with high rate discovery does not change until a complete set of low rate discovery information has been transmitted. 
       FIG. 11  is a flowchart  1100  of an exemplary method of operating a first node to assist in communicating peer discovery information corresponding to a second node. The first node is, e.g., one of peer discovery assist node  114  and server node  112 , of system  100  of  FIG. 1 , and the second node is, e.g., one of peer to peer communications devices ( 102 ,  104 ,  106 ,  108 ,  110 ) of system  100  of  FIG. 1 . Steps  1   104 ,  1108  and  1110  are optional steps which are included in some, but not necessarily all, embodiments. Steps  1107  and  1113  are also optional steps included in some, but not necessarily all, embodiments, e.g., included in an embodiment in which the first node is assisting in communicating peer discovery information corresponding to both a second node and a third node. 
     In one embodiment in which steps  1104 ,  1108  and  1110  are omitted, operation proceeds from step  1102  to step  1106  and from step  1106  to step  1112 . In another exemplary embodiment in which steps  1104 ,  1108  and  1110  are omitted, operation proceeds from step  1102  to step  1106  and  1107 ; operation proceeds from step  1106  to step  1112 , and operation proceeds from step  1107  to step  1113 . 
     The flowchart will be described for an embodiment in which steps  1104 ,  1108  and  1110  are included. Operation starts in step  1102  and proceeds to step  1104 , in which the first node stores timing structure information indicating a recurring pattern of peer discovery reception intervals and peer discovery transmission intervals. Operation proceeds from step  1104  to step  1106 . In step  1106 , the first device receives, over an airlink, portions of one or more sets of peer discovery information from a second node, said portions being received at a first rate. Operation proceeds from step  1106  to step  1108 . 
     In step  1108 , the first device determines if the current time information and the stored timing structure information indicate that the first node should switch from receive to transmit. If the determination of step  1108  is not to switch, then operation proceeds back to the input of step  1108 . However, if the determination of step  1108  is to switch, then operation proceeds from step  1108  to step  1110 . In step  1110  the first node is controlled to switch between receiving and transmitting based on the stored timing structure information. Operation proceeds from step  1110  to step  1112 . In step  1112  the first device transmits over an airlink at a second rate which is faster than the first rate, received portions of peer discovery information corresponding to the second node. 
     In some embodiments, transmitting over an airlink at a second rate includes transmitting individual received portions of a set of peer discovery information multiple times. In some embodiments, transmitting over an airlink at a second rate includes transmitting a full set of peer discovery information for each received portion of peer discovery information. 
     In some embodiments, a set of peer discovery information includes N portions and each of the N portions is transmitted N times. 
     In some embodiments, a previously received set of peer discovery information is transmitted between two consecutively received portions of peer discovery information. 
     In some embodiments, the first node supports concurrent discovery assistance to a plurality of nodes which are transmitting discovery information at a low rate. For example, in some embodiments, the first node also assists in communicating peer discovery information corresponding to a third node. In one such embodiment, the method of flowchart  1100  includes steps  1107  and  1113 . In step  1107 , which may be performed in parallel with step  1106  in one embodiment, the first node receives, over an airlink, portions of one or more sets of peer discovery information from the third node, said portions being received at the first rate. In step  1113 , which may be performed in parallel to step  1112  in one embodiment, the first node transmits over an airlink at the second rate which is faster than the first rate, received portions of peer discovery information corresponding to the third node. 
     In some exemplary embodiments step  1107  is performed in series with step  1106 . In some exemplary embodiments step  1113  is performed in series with step  1112 . 
       FIG. 12  is a flowchart  1200  of an exemplary method of operating a node, e.g., an assist node or a server node such as a base station, to assist in communicating discovery information. Operation of the exemplary method starts in step  1202  and proceeds to step  1204 , where the node stores peer to peer timing structure information as stored peer to peer timing structure information  1205 . The storing of step  1205  is, e.g., part of a node configuration and/or node initialization process. The stored peer to peer timing structure information  1205  includes, e.g., information identifying a plurality of discovery interval air link resources, information associating particular discovery interval air link resources with particular device identifiers and information indicating a recurring discovery interval pattern. 
     Operation proceeds from step  1204  to step  1206 , in which the node determines time with respect to the peer to peer timing structure. In some embodiments, a reference signal is received via the backhaul to coordinate timing, while in other embodiments, a reference signal is received via the air interface to determine time and synchronize with respect to the peer to peer timing structure. Operation proceeds from step  1206  to step  1208 . In step  1208 , which is performed on an ongoing basis, the node maintains timing and outputs current time  1209 . 
     Operation also proceeds from step  1206  to steps  1210 ,  1212 ,  1214  and connecting node A  1216 . In step  1210 , which is performed on an ongoing basis, the node monitors for discovery signals, e.g., from peer to peer wireless terminals in its local vicinity which are transmitting. Detected device IDs  1211  is an output of monitoring  1210 . In some embodiments, at different times different devices may be associated with the same device identifier. For example, a device identifier, associated with a particular set of discovery interval air link resources which map to that ID, is temporarily acquired by and held by a wireless terminal which desires to be active. 
     Step  1212  is performed for each of one or more of the detected device IDs. In step  1212 , the node categorizes the wireless terminal associated with the device ID as being in one of a low rate discovery node or a high rate discovery mode. For example, if the node detects discovery signals during the low rate discovery intervals associated with the device ID on the air link resource associated with the device ID but does not detect discovery signals during the additional discovery intervals associated with the device ID on the air link resources associated with the device ID, the node concludes that the wireless terminal currently associated with the device ID is operating in low rate mode of transmitting discovery information. Conversely if the node detects discovery signals on the air link resources associated with the device ID corresponding to both low rate discovery resources and additional resources, the node concludes that the wireless terminal associated with the device ID is to be categorized as being in high rate discovery mode of transmitting discovery information. Detected device IDs  1211  is an input to step  1212 , while device IDs of wireless terminals in low rate discovery mode  1213  is an output of step  1212 . 
     Step  1214  is performed for each of the wireless terminals in low rate discovery mode. In step  1214 , the node determines whether or not to act as a discovery assist node for the wireless terminal. Information  1215 , identifying the device IDs of wireless terminals to be assisted by the node, is an output of step  1214 . 
     Operation proceeds from step  1206  via connecting node A  1216  to step  1218  for each of the wireless terminals being assisted in accordance with information  1215 . In step  1218 , which is performed on an ongoing basis, the node identifies an upcoming time interval discovery resource associated with the device ID currently held by the WT being assisted. Current time  1209 , stored recurring peer to peer timing structure information  1205  and device IDs of wireless terminals to be assisted  1215  are inputs to step  1218 . Operation proceeds from step  1218  to step  1220  for each identified interval discovery resource associated with the device identifier. 
     In step  1220  the node determines whether the identified interval discovery resource is a low rate interval discovery resource or an additional interval discovery resource. If the identified interval air link resource is a low rate interval air link discovery resource, then operation proceeds from step  1220  to step  1222 ; however, if the identified interval discovery resource is an additional interval air link discovery resource, then operation proceeds from step  1220  to step  1228 . 
     Returning to step  1222 , in step  1222  the node configures to receive during the interval. Then, in step  1224  the node receives a discovery information portion from the wireless terminal associated with the device ID. Operation proceeds from step  1224  to step  1226 . In step  1226 , the node stores the received discovery information portion as stored discovery information portion  1227  and also stores time tag information and device ID information associated with the received discovery information portion as information  1229 . 
     Returning to step  1228 , in step  1228  the node configures to transmit during the interval. Operation proceeds from step  1228  to step  1230 . In step  1230  the node checks as to whether or not an appropriate stored discovery information portion is available to be transmitted using the additional interval resource in accordance with transmission pattern information. Step  1230  uses as inputs available pairs of stored information ( 1227 ,  1229 ) and stored recurring timing structure information  1205 . Note that a particular discovery information portion, scheduled for retransmission in the identified interval using the additional interval discovery resource in accordance with timing structure, may be unavailable to the node, e.g., due to the wireless terminal having just started transmitting or due to a failed reception of a discovery signal portion because of a weak signal or because of interference. 
     If in step  1230 , the node determines that the stored information which is scheduled for transmission during the identified interval is not available, then operation proceeds from step  1230  to step  1232 , where the node refrains from transmitting during the interval on the additional interval air link resource. However, if in step  1230  the node determines that the stored information which is scheduled for transmission during the identified interval is available for transmission, then operation proceeds from step  1230  to step  1234  where the node generates a signal to repeat discovery information received during a previous interval in accordance with a discovery information repeat pattern for the stored peer to peer timing structure. Operation proceeds from step  1234  to step  1236  in which the node transmits the generated signal during the interval using the additional discovery interval air link resource, e.g., segment. When the node performs step  1236 , the node is acting as a proxy for the wireless terminal in low rate discovery information transmit mode, transmitting the same information during that interval that the wireless terminal would have transmitted if it had been in high rate discovery information transmit mode. This proxy operation facilitates the rapid recovery of the discovery information by another peer to peer device. 
     In one exemplary embodiment, in which low rate discovery information portions are generated in sets of N portions, when in a steady state of operation providing discovery assistance for a wireless terminal, for one execution of the reception of a discovery information portion from the wireless terminal, e.g., step  1224 , there are N executions of step  1236  in which the node retransmits a received discovery information portion. In the example, of the example of  FIG. 14 , N=4.  FIGS. 9 and 10  illustrate two exemplary patterns which may be utilized by a wireless terminal and an assist node. With respect to  FIG. 9  or  10 , consider that a wireless terminal is in low rate discovery mode and transmits using the low rate discovery interval air link resources, identified by crosshatch shading, and is quiescent with regard to the discovery interval additional air link resources identified by no shading. Now consider that an assist node executing the method of flowchart  1200  of  FIG. 12 , receives during the low rate discovery intervals on the low rate air link resources identified by crosshatch shading, and stores away the received portions for later retransmission. Also consider that the assist node transmits during the additional discovery intervals using the additional discovery interval air link resources identified by no shading. It may be observed that discovery information portions corresponding to an additional discovery interval communicate information which had been transmitted in a prior low rate discovery interval in accordance with the recurring structure. 
       FIG. 13  is a drawing of an exemplary communications node  1300 , e.g., a peer discovery assist node or server node such as a base station node, in accordance with an exemplary embodiment. Exemplary communications node  1300  is, e.g., one of peer discovery assist node  114  and server node  112  of system  100  of  FIG. 1 . 
     Communications node  1300  includes a wireless receiver module  1302 , a wireless transmitter module  1304 , a processor  1306 , user I/O devices  1308 , and a memory  1310  coupled together via a bus  1312  over which the various elements may interchange data and information. In some embodiments, communications node  1300  also includes network interface  1307  which is coupled to bus  1312 . Network interface  1307  couples the communications node  1300  to other network nodes and/or the Internet, e.g., via a wired backhaul network. 
     Memory  1310  includes routines  1318  and data/information  1320 . The processor  1306 , e.g., a CPU, executes the routines  1318  and uses the data/information  1320  in memory  1310  to control the operation of the communications node  1300  and implement methods, e.g., the method of flowchart  1100  of  FIG. 11  or the method of flowchart  1200  of  FIG. 12 . 
     Wireless receiver module  1302 , e.g., an OFDM or CDMA receiver, is coupled to receive antenna  1314  via which the communications device  1300  receives signals from other wireless devices, e.g., peer discovery information signals conveying portions of peer discovery information from peer to peer device devices. In some embodiments, the communications device  1300  synchronizes to a timing structure, e.g., a peer to peer recurring timing structure, via one or more signals received via wireless receiver module  1302 , e.g., a via a received OFDM beacon signal from beacon transmitter  116 . 
     Wireless transmitter module  1304 , e.g., an OFDM or CDMA transmitter, is coupled to transmit antenna  1316  via which the communications node  1300  transmits signals to wireless devices. Transmitted signals include signals conveying received peer discovery information portions which are being broadcast to assist in communicating peer discovery information at a higher rate. 
     Wireless receiver module  1302  receives over an airlink portions of one or more sets of peer discovery information from another node, e.g., a first peer to peer wireless terminal, said portions being received at a first rate. Wireless transmitter module  1304  transmits over an airlink at a second rate which is faster than the first rate, received portions of peer discovery information corresponding to the another node. In some embodiments, transmitting over an airlink at a second rate includes transmitting individual received portion of a set of peer discovery information multiple times. In some embodiments, transmitting over an airlink at a second rate includes transmitting a full set of peer discovery information for each received portion of a set of peer discovery information. In some embodiments, a set of peer discovery information includes N portions and each of the N portions is transmitted N times. In some embodiments, a previously received set of peer discovery information is transmitted between two consecutively received portions of peer discovery information. In some embodiments, the communications node  1300  supports discovery assistance for multiple devices concurrently, e.g., retransmitting received recovered discovery information portions corresponding to two or more different wireless terminals broadcasting discovery information at a low rate in accordance with a recurring timing and frequency structure recognized by the communications node and the two or more different wireless terminals. 
     User I/O devices  1308  include, e.g., microphone, keyboard, keypad, camera, speaker, display, etc. User I/O devices  1308  allow an operator of communications device  1300  to input data/information, access output data/information, and control at least some functions of the communications node  1300 , e.g., activate peer discovery assist functionality, input peer discovery assist determination and/or screening criteria, etc., control configuration, and/or control loading of timing/frequency structure information. 
     Network interface  1307  couples the communications node  1300  to other network nodes, e.g., servers, routers, base stations, AAA node, system control nodes, timing reference nodes, etc., and/or the Internet. In some embodiments, communications node  1300  synchronizes to a timing structure, e.g., a peer to peer recurring timing structure, via signaling communicated over the network interface  1307 . 
     Routines  1318  include a communications routine  1322  and control routines  1324 . The communications routine  1322  implements the various communications protocols used by the communications node  1300 . The control routines  1324  include a peer discovery portion recovery module  1326 , an assist control module  1328 , a mode control module  1330 , a node identification module  1332 , a discovery information rate determination module  1334 , an assist decision module  1336  and an assist signal generation module  1338 . Data/information  1320  includes stored timing structure information  1339 , recovered peer discovery portions  1352 , generated assist signals  1354 , information identifying a current receive/transmit mode  1356 , identified wireless terminals transmitting discovery information  1358 , information identifying the discovery information modes of wireless terminals transmitting discovery information  1360 , and information identifying wireless terminals being assisted  1362 . 
     Peer discovery portion recovery module  1326  recovers received portions of peer discovery information being communicated from other devices, e.g., portions of peer discovery information being communicated from peer to peer wireless devices being communicated using low rate peer discovery air link resources. Recovered peer discovery portions  1352  include stored recovered received peer discovery portions from peer discovery portion recovery module  1326 . Some transmitted peer discovery portions of interest may not be recovered, e.g., due to a weak received signal or interference. In various embodiments, although a discovery information portion may be successfully recovered by module  1326  and available for subsequent re-transmission, some or all of the underlying pre-encryption discovery information is not accessible to node  1300 . For example, device  1300  may not include a particular decryption module or have access to a key needed to decrypt an encrypted discovery information portion. Thus device  1300  can perform proxy assistance, yet security may be maintained between trusted and/or authorized users. Stored recovered received peer discovery portions  1352  are available for later retransmission, e.g., during an appropriate additional discovery interval in accordance with the timing/frequency structure information. 
     Assist control module  1328  controls the wireless transmitter module  1304  to transmit assist signals conveying received recovered portions of peer discovery information corresponding to another node, e.g., a peer to peer wireless terminal, at a second rate. The second rate at which the communications node  1300  is controlled to transmit received recovered portions of peer discovery information corresponding to another node is faster than a first rate at which the communications node  1300  is controlled to receive peer discovery information portions from the another node. For example, in the example of  FIG. 14 , the assist node transmits four received recovered discovery information portions for each received recovered portion. 
     In various embodiments, transmitting over an airlink at a second rate includes transmitting individual received portions of a set of peer discovery information multiple times. For example consider that communications node  1300  is a timing/frequency structure in accordance with  FIG. 9 , that a wireless terminal in low rate discovery transmit mode is transmitting discovery information portions using the low rate discovery air link resources indicated by crosshatch shading, and that the communications node  1300  is transmitting using the additional discovery interval resources indicated by no shading. In such a scenario, device  1300  received and recovers discovery information portion A N-1  as indicated by arrow  904 , but subsequently transmits portion A N-1  four times as indicated by arrows  912 ,  920 ,  928 , and  936 . Similarly, device  1300  receives and recovers discovery information portion B N-1  as indicated by arrow  914 , but subsequently transmits portion B N-1  four times as indicated by arrows  922 ,  930 ,  938 , and  946 . Similarly, device  1300  receives and recovers discovery information portion C N-1  as indicated by arrow  924 , but subsequently transmits portion C N-1  four times as indicated by arrows  932 ,  940 ,  948 , and  946 . Similarly, device  1300  receives and recovers discovery information portion D N-1  as indicated by arrow  934 , but subsequently transmits portion D N-1  four times as indicated by arrows  942 ,  950 ,  958 , and  966 . 
     In some embodiments, transmitting over an airlink at a second rate includes transmitting a full set of peer discovery information for each received portion of peer discovery information. Continuing with the above example using  FIG. 9 , there are 4 full sets of peer discovery information transmitted corresponding to four received portions of the set of peer discovery, where the set of peer discovery information is the set of {portion A N-1 , portion B N-1 , portion C N-1 , portion D N-1 }. 
     In some embodiments, a set of peer discovery information includes K portions and each of the K portions is transmitted N times. Further continuing with the above example using  FIG. 9 , a set of peer discovery information has four portions, so K=4, and each of the four portions is transmitted 4 times. 
     In some embodiments, a previously received set of peer discovery information can be, and sometimes is, transmitted between two consecutively received portions of peer discovery information. Continuing with the above example using  FIG. 9 , previously received set of peer discovery information {A N-1 , B N-1 , C N-1 , D N-1 } is transmitted between consecutively received portions D N-1  and A N  as indicated by arrows  934 ,  936 ,  938 ,  940 ,  942 ,  944 . Now consider the alternative timing/frequency mapping pattern illustrated by  FIG. 10 , and again assume that communications device  1300  receives for low rate discovery interval resources indicated by crosshatch shading and transmits for additional discovery interval resources indicated by no shading. In this exemplary embodiment, a previously received set of peer discovery information is transmitted between two consecutively received portions of peer discovery information. For example, between received portions A N  and B N , as indicated by arrows  1044  and  1054 , the previously received set of peer discovery information {A N-1 , B N-1 , C N-1 , D N-1 } is transmitted as indicated by arrows  1052 ,  1046 ,  1048 ,  1050 . Similarly, between received portions B N  and C N , as indicated by arrows  1054  and  1064 , the previously received set of peer discovery information {A N-1 , B N-1 , C N-1 , D N-1 } is transmitted as indicated by arrows  1060 ,  1062 ,  1056 ,  1058 . 
     Mode control module  1330  controls the communications node to switch between receiving and transmitting based on the stored timing structure information. Current Rx/TX mode  1356  identifies whether the node  1300  is in a receive mode, e.g., for receiving discovery information in a low rate peer discovery interval, or in a transmit mode, e.g., for transmitting discovery information in an additional discovery interval. 
     Node identification module  1332  identifies that peer discovery information is being transmitted from wireless terminals which currently correspond to particular identifiers. In some embodiments, particular air link resources, e.g., segments, in the timing/frequency structure are associated with particular device identifiers. Thus by detecting a discovery information portion on a particular low rate discovery interval resource, communications node  1300  can identify that a wireless terminal associated with that device identifier is currently active with regard to the broadcasting of discovery information. Identified wireless terminals transmitting discovery information  1358  is an output of node identification module  1330 . For example, each of a plurality of identifiers may be associated with a set of air link resources designated for peer discovery. If communications node  1300  has recovered a received peer discovery signal on a particular resource, node identification module can conclude that the wireless terminal currently corresponding to that resource is active. 
     A peer to peer wireless terminal may be transmitting peer discovery information at a low rate or at a high rate using air link resources, e.g., segments associated with its currently held identifier. While in low rate, the peer to peer wireless terminal transmits on its low rate peer discovery interval resources during its low rate discovery intervals, but refrains from transmitting on its additional discovery interval resources during its additional discovery intervals. Discovery information rate determination module  1334  determines whether a wireless terminal which is actively transmitting discovery information is in a high rate transmit mode with regard to discovery information or a low rate transmit mode with regard to discovery information. Discovery information modes of wireless terminals transmitting discovery information  1360  is an output of discovery information rate determination module  1334 . 
     Lack of detection of received recovered discovery information on additional discovery intervals air link resources corresponding to a device identifier can be used by discovery information rate determination module  1334  to determine that the wireless terminal corresponding to the device identifier is in low rate mode. The detection of received recovered discovery information on additional discovery intervals air link resources corresponding to a device identifier can be used by discovery information rate determination module  1334  to determine that the wireless terminal corresponding to the device identifier is either in high rate mode or is already being assisted by another node. In some embodiments, the communications node does not distinguish between a condition in which a peer to peer wireless terminal is in high rate discovery information transmit mode or the peer to peer wireless terminal is in low rate discovery information transmit mode but is already being assisted by another node. In some other embodiments, the communications node  1300  attempts to distinguish between the two scenarios, e.g., by comparing received signals corresponding to the same device identifier but received during a low rate peer discovery interval and an additional discovery interval, e.g., in terms of received power, received SNR and/or received SINR. In some embodiments, a flag is used to distinguish between whether the discovery portion is sourced from an original node or a node acting as an assist node. 
     Assist decision module  1336  determines whether or not communications device  1300  is to assist in the communication of discovery information for a wireless terminal corresponding to a device identifier which has been determined to be transmitting discovery information in low rate discovery transmit mode. Information  1360  is an input to assist decision module  1336  while information identifying wireless terminals being assisted  1362  is an output of assist decision module  1336 . 
     Assist signal generation module  1338  generates an assist signal, e.g., a signal including a recovered peer discovery portion communicated during a low rate discovery interval, to be communicated during an additional discovery interval corresponding to the same device identifier, in accordance with the pattern information of the stored timing structure, for a wireless terminal which communications device  1300  has decided to assist. Thus for a wireless terminal, which communications device  1300  has decided to assist, the communications device  1300  generates assist signals and transmits those assist signals using the discovery interval segments of the additional discovery intervals corresponding to the device identifier. 
     The stored timing/frequency structure information  1339  includes a plurality of sets of information identifying peer discovery interval resources corresponding to different identifiers which may be temporarily associated with a wireless terminal (information identifying peer discovery interval resources for device identifier ID  1   1340 , . . . , information identifying peer discovery interval resource for device identifier ID N  1346 ), an mapping pattern information  1351 . Information identifying peer discovery interval resources for device identifier ID  1   1340  includes information identifying low rate peer discovery interval resources  1342  and information identifying additional discovery interval resources  1344 . Similarly, information identifying peer discovery interval resources for device identifier ID N  1346  includes information identifying low rate peer discovery interval resources  1348  and information identifying additional discovery interval resources  1350 . 
     The stored timing structure information  1339  includes information indicating a recurring pattern of peer discovery reception intervals and peer discovery transmission intervals, e.g., for times in which the communications node  1300  is to assist another node, e.g., a peer to peer wireless terminal in low rate discovery transmit mode, in communicating peer discovery information. For example, assume that the communications device  1300  is assisting the wireless terminal which is currently holding the identifier  1 , then information identifying low rate peer discovery interval resources  1342  indicates intervals and segments that communications node  1300  should consider peer discovery reception intervals and resources, while information indicating additional discovery interval resources  1344  indicates intervals and segments that communications node  1300  should consider peer discovery transmission intervals and segments. Alternatively, or in addition, consider that the communications device  1300  is assisting the wireless terminal which is currently holding the identifier N, then information identifying low rate peer discovery interval resources  1348  indicates intervals and segments that communications node  1300  should consider peer discovery reception intervals and segments while information indicating additional discovery interval resources  1350  indicates intervals and segments that communications node  1300  should consider peer discovery transmission intervals and segments. 
     Mapping pattern information  1351  includes information identifying portions of information to be associated with particular discovery information resources in the recurring timing and frequency structure. For example, information  1351  defines mapping of discovery information portions to an indexed set of discovery resources in the recurring timing/frequency structure. Corresponding to a device identifier, mapping pattern information  1351  includes information identifying which prior transmitted portion which has been received on a low rate discovery resource is to retransmitted on a particular additional discovery resource.  FIG. 9  and  FIG. 10  illustrate examples of some information defined by mapping pattern information for two exemplary embodiments. 
       FIG. 14  is a drawing  1400  illustrating exemplary nodes in a peer to peer communications system and the transmission of discovery information. The exemplary nodes include a first wireless terminal  1402 , e.g., a peer to peer mobile node, which is operating in a high rate discovery mode and which is transmitting discovery information at a high rate, as indicated by discovery signals  1412  being transmitted along time axis  1410 . The exemplary nodes also include a second wireless terminal  1404 , e.g., a second peer to peer mobile node, which is operating in a low rate discovery mode and which is transmitting discovery information at a low rate, as indicated by discovery signals  1414  being transmitted along time axis  1410 . Similarly, third wireless terminal  1406 , e.g., a third peer to peer mobile node, which is operating in a low rate discovery mode is transmitting discovery information at a low rate, as indicated by discovery signals  1416  being transmitted along time axis  1410 . Exemplary node  1408 , e.g., an assist node or server node such as a base station, is also included. Node  1408 , has recognized that WT  2   1404  and WT  3   1406  are transmitting discovery information at a low rate, has made a decision to assist both nodes ( 1404 ,  1406 ) and is transmitting discovery information using the air link resources which wireless terminal  2   1404  and wireless terminal  1406  would have used if the nodes had been in high rate discovery mode instead of low rate discovery mode. Discovery information signals  1418  transmitted by node  1408  includes copies of previously transmitted discovery information signals transmitted by WT  2   1404  and  1406 , e.g., in accordance with a predetermined transmission pattern sequence such as one represented by  FIG. 9  or  FIG. 10 . 
       FIG. 15  is a drawing illustrating an exemplary peer to peer wireless terminal  1502 , an exemplary assist node  1504 , air link resources associated with communicating discovery information portions, and exemplary signaling in accordance with one exemplary embodiment. In this example, peer to peer wireless terminal  1502  is currently in a low rate discovery transmit mode, and assist node  1504  is currently assisting wireless terminal  1502  in the communication of discovery information portions. Assume that wireless terminal  1502  has generated a first set of discovery information portions which is the set of {portion A N-1    1501 , portion B N-1    1503 , portion C N-1    1505 , portion D N-1    1507 } and a second set of discovery information portions which is the set of {portion A N    1509 , portion B N    1511 , portion C N    1513 , portion D N    1515 }. Assume that wireless terminal  1502  has previously transmitted discovery information portions A N-1    1501 , B N-1    1503 , C N-1    1505 , and D N-1    1507  using prior low rate discovery interval air link resources, e.g., segments, and that assist node has received such transmissions and stored the received portions in its memory to be available for re-transmission. 
     Drawing  1508  plots frequency on the vertical axis  1514  vs time on the horizontal axis  1512  and illustrates discovery interval air link resources ( 1516 ,  1518 ,  1520 ,  1522 ,  1524 ,  1526 ,  1528 ,  1530 ,  1532 ,  1534 ,  1536 ,  1538 ,  1540 ,  1542 ,  1544 ,  1546 ,  1548 ,  1550 ,  1552 ,  1554 ), e.g., segments or transmission units, associated with the device identifier currently held by wireless terminal  1502 . Air link resources ( 1516 ,  1526 ,  1536 ,  1546 ) indicated by crosshatch shading are low rate discovery air link resources, while air link resources ( 1518 ,  1520 ,  1522 ,  1524 ,  1528 ,  1530 ,  1532 ,  1534 ,  1538 ,  1540 ,  1542 ,  1544 ,  1548 ,  1550 ,  1552 ,  1554 ) indicated by no shading are additional discovery air link resources. 
     Drawing  1506  illustrates signaling transmitted by peer to peer wireless terminal  1502 , while drawing  1510  illustrates signaling transmitted by assist node  1504 . Wireless terminal  1502  transmits signal  1556  conveying discovery information portion A N    1509  using low rate discovery air link resource  1516 . This transmitted signal  1556  is received and recovered by assist node  1504  which stores discovery information portion A N    1509 . Assist node  1504  transmits signal  1558  conveying discovery information portion B N-1    1503  using additional discovery interval air link resource  1518 . Assist node  1504  transmits signal  1560  conveying discovery information portion C N-1    1505  using additional discovery interval air link resource  1520 . Assist node  1504  transmits signal  1562  conveying discovery information portion D N-1    1507  using additional discovery interval air link resource  1522 . Assist node  1504  transmits signal  1564  conveying discovery information portion A N    1509  using additional discovery interval air link resource  1524 . 
     Wireless terminal  1502  transmits signal  1566  conveying discovery information portion B N    1511  using low rate discovery air link resource  1526 . This transmitted signal  1566  is received and recovered by assist node  1504  which stores discovery information portion B N    1511 . Assist node  1504  transmits signal  1568  conveying discovery information portion C N-1    1505  using additional discovery interval air link resource  1528 . Assist node  1504  transmits signal  1570  conveying discovery information portion D N-1    1507  using additional discovery interval air link resource  1530 . Assist node  1504  transmits signal  1572  conveying discovery information portion A N    1509  using additional discovery interval air link resource  1532 . Assist node  1504  transmits signal  1574  conveying discovery information portion B N    1511  using additional discovery interval air link resource  1534 . 
     Wireless terminal  1502  transmits signal  1576  conveying discovery information portion C N    1513  using low rate discovery air link resource  1536 . This transmitted signal  1576  is received and recovered by assist node  1504  which stores discovery information portion C N    1513 . Assist node  1504  transmits signal  1578  conveying discovery information portion D N-1    1507  using additional discovery interval air link resource  1538 . Assist node  1504  transmits signal  1580  conveying discovery information portion A N    1509  using additional discovery interval air link resource  1540 . Assist node  1504  transmits signal  1582  conveying discovery information portion B N    1511  using additional discovery interval air link resource  1542 . Assist node  1504  transmits signal  1584  conveying discovery information portion C N    1513  using additional discovery interval air link resource  1544 . 
     Wireless terminal  1502  transmits signal  1586  conveying discovery information portion D N    1515  using low rate discovery air link resource  1546 . This transmitted signal  1586  is received and recovered by assist node  1504  which stores discovery information portion D N    1515 . Assist node  1504  transmits signal  1588  conveying discovery information portion A N    1509  using additional discovery interval air link resource  1548 . Assist node  1504  transmits signal  1590  conveying discovery information portion B N    1511  using additional discovery interval air link resource  1550 . Assist node  1504  transmits signal  1592  conveying discovery information portion C N    1513  using additional discovery interval air link resource  1552 . Assist node  1504  transmits signal  1594  conveying discovery information portion D N    1515  using additional discovery interval air link resource  1554 . 
     Exemplary wireless terminal  1502  is, e.g., one of the peer to peer wireless terminals ( 102 ,  104 ,  106 ,  108 ,  110 ) of  FIG. 1 . Exemplary assist node  1504  is, e.g., one of nodes ( 112 ,  114 ) of  FIG. 1 . The combination of the discovery signaling from peer to peer wireless terminal  1502  and assist node  1504 , appears to another peer to peer wireless terminal in the vicinity of nodes ( 1502 ,  1504 ), as if peer to peer wireless terminal  1502  is transmitting in a high rate discovery transmit mode. This facilitates rapid recovery of discovery information originally sourced from wireless terminal  1502  without wireless terminal  1502  having to perform each of the transmissions. Thus peer to peer wireless terminal  1502 , which may be a mobile device, is allowed to conserve battery power, yet its discovery information is being made available to other devices at a high rate because of the assistance provided by assist node  1504 . 
     The techniques of various embodiments may be implemented using software, hardware and/or a combination of software and hardware. Various embodiments are directed to apparatus, e.g., mobile nodes such as mobile access terminals, base stations including one or more attachment points, and/or communications systems. Various embodiments are also directed to methods, e.g., method of controlling and/or operating mobile nodes, base stations and/or communications systems, e.g., hosts. Various embodiments are also directed to machine, e.g., computer, readable medium, e.g., ROM, RAM, CDs, hard discs, etc., which include machine readable instructions for controlling a machine to implement one or more steps of a method. 
     In various embodiments nodes described herein are implemented using one or more modules to perform the steps corresponding to one or more methods, for example, receiving a signal, determining a best connection for a carrier of interest, calculating a service level indicating metric for a current attachment point, calculating a service level indicating metric for an alternative attachment point, making a handoff decision. Thus, in some embodiments various features are implemented using modules. Such modules may be implemented using software, hardware or a combination of software and hardware. Many of the above described methods or method steps can be implemented using machine executable instructions, such as software, included in a machine readable medium such as a memory device, e.g., RAM, floppy disk, etc. to control a machine, e.g., general purpose computer with or without additional hardware, to implement all or portions of the above described methods, e.g., in one or more nodes. Accordingly, among other things, various embodiments are directed to a machine-readable medium including machine executable instructions for causing a machine, e.g., processor and associated hardware, to perform one or more of the steps of the above-described method(s). Some embodiments are directed to a device, e.g., communications device, including a processor configured to implement one, multiple or all of the steps of one or more methods of the invention. 
     Some embodiments are directed to a computer program product comprising a computer-readable medium comprising code for causing a computer, or multiple computers, to implement various functions, steps, acts and/or operations, e.g. one or more steps described above. Depending on the embodiment, the computer program product can, and sometimes does, include different code for each step to be performed. Thus, the computer program product may, and sometimes does, include code for each individual step of a method, e.g., a method of controlling a communications device or node. The code may be in the form of machine, e.g., computer, executable instructions stored on a computer-readable medium such as a RAM (Random Access Memory), ROM (Read Only Memory) or other type of storage device. In addition to being directed to a computer program product, some embodiments are directed to a processor configured to implement one or more of the various functions, steps, acts and/or operations of one or more methods described above. Accordingly, some embodiments are directed to a processor, e.g., CPU, configured to implement some or all of the steps of the methods described herein. The processor may be for use in, e.g., a communications device or other device described in the present application. 
     In some embodiments, the processor or processors, e.g., CPUs, of one or more devices, e.g., communications devices such as wireless terminals are configured to perform the steps of the methods described as being as being performed by the communications device. Accordingly, some but not all embodiments are directed to a device, e.g., communications device, with a processor which includes a module corresponding to each of the steps of the various described methods performed by the device in which the processor is included. In some but not all embodiments a device, e.g., communications device, includes a module corresponding to each of the steps of the various described methods performed by the device in which the processor is included. The modules may be implemented using software and/or hardware. 
     While described in the context of an OFDM system, at least some of the methods and apparatus of various embodiments are applicable to a wide range of communications systems including many non-OFDM and/or non-cellular systems. 
     Numerous additional variations on the methods and apparatus of the various embodiments described above will be apparent to those skilled in the art in view of the above description. Such variations are to be considered within the scope. The methods and apparatus may be, and in various embodiments are, used with CDMA, orthogonal frequency division multiplexing (OFDM), and/or various other types of communications techniques which may be used to provide wireless communications links between access nodes and mobile nodes. In some embodiments the access nodes are implemented as base stations which establish communications links with mobile nodes using OFDM and/or CDMA. In various embodiments the mobile nodes are implemented as notebook computers, personal data assistants (PDAs), or other portable devices including receiver/transmitter circuits and logic and/or routines, for implementing the methods.