Abstract:
Wireless communications devices, e.g., peer to peer mobile wireless terminals in and ad-hoc peer to peer communications network, support multiple modes of peer discovery operation. In different peer discovery transmit modes peer discovery information is transmitted at different rates. In different peer discovery receive modes peer discovery information is monitored at different rates. Performing peer discovery operations at a higher rate has the benefit of reducing discovery latency at the cost of utilizing more communications resources and expending more power. A communications device dynamically changes its mode in response to changing conditions and/or needs. Transitions between modes are in response to a determined change condition trigger occurrence. Various change condition triggers include, e.g., a user event, an application event, information received over the air interface, information derived from information received over the air interface and/or temporal information.

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 and/or receiving discovery information may be considered overhead signaling, and resources such as power and spectrum over time expended for discovery information signaling may be unavailable for traffic signaling. The power expended by a mobile wireless communications device for transmitting and/or receiving discovery information and the reserve battery power remaining are important considerations in implementing a structure supporting the communication of discovery information. 
     Based on the above discussion it should be appreciated that there is a need for methods and/or apparatus that support the communication of a wide range of different types of discovery information in an efficient manner and that methods and/or apparatus that allow for flexibility in the transmission and/or reception of discovery information would be beneficial. 
     SUMMARY 
     Various embodiments are related to methods and apparatus for use in a mobile wireless system that enables direct wireless communications between subscriber devices, e.g., an ad hoc peer-to-peer network. In some embodiments, a process referred to as peer discovery enables autonomous detection of peers, networks and/or services of interest to a particular subscriber device. In some instance implemented peer discovery methods and apparatus 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 one rate, e.g., a low rate, while other devices may be performing peer discovery at another 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 communications resources and expending more power, e.g., reducing battery lifetime. In accordance with a feature of some embodiments, a subscriber device, participating in peer discovery dynamically adapts its rate of sending and/or monitoring peer discovery information. 
     Various embodiments include one or more of a wide range of approaches and triggers for controlling the dynamic adaptation. For example, in some instances, a peer discovery rate change, e.g., from a low rate of operation to high rate operation, can be triggered by a user and/or application event, e.g., starting an application, selecting or transitioning to a particular application mode, or choosing a particular menu option. In other instances, a peer discovery rate change can be triggered or determined based on information received over the air interface, e.g., detecting a partial match of peer discovery information already being monitored for, detecting a new node within local proximity, or detecting a predetermined rate of change of the set of nodes within local proximity. In still other instances a peer discovery rate change can be triggered or determined based on temporal information, e.g., preconfigured or learned information indicating the time of day, days of the week, etc., when peer discovery should be performed at a given rate. In some embodiments, it is possible to independently control the rate of sending peer discovery information and the rate of monitoring peer discovery information. However, in some embodiments, it may be beneficial to couple the rate of sending and monitoring, and the rate of sending and monitoring are controllably coupled. 
     An exemplary method of operating a communications device which supports multiple peer discovery modes including a first transmit peer discovery mode during which peer discovery signals are transmitted at a first rate and a second transmit peer discovery mode during which peer discovery signals are transmitted at a second rate, said second rate being higher than the first rate, includes: while operating in said first transmit peer discovery mode, determining if a change condition used to trigger a change from the first mode to the second mode occurred; and upon detecting that said change condition used to trigger a change from the first mode to the second mode has occurred, transitioning from the first mode to the second mode. An exemplary communications device which supports multiple peer discovery modes including a first transmit peer discovery mode during which peer discovery signals are transmitted at a first rate and a second transmit peer discovery mode during which peer discovery signals are transmitted at a second rate, said second rate being higher than the first rate, comprises: a first transition condition detection module for determining if a change condition used to trigger a change from the first mode to the second mode occurred when said communications device is operating in said first mode; and a first mode transition control module for controlling said communications device to transition from the first mode to the second mode when said first transition condition detection module detects that said change condition used to trigger a change from the first mode to the second mode has occurred. 
     An exemplary method of operating a communications device which supports multiple peer discovery modes including a first receive peer discovery mode during which peer discovery signals are monitored at a first rate and a second receive peer discovery mode during which peer discovery signals are monitored at a second rate, said second rate being higher than the first rate, comprises: while operating in said first receive peer discovery mode, determining if a change condition used to trigger a change from the first mode to the second mode occurred; and upon detecting that said change condition used to trigger a change from the first mode to the second mode has occurred, transitioning from the first mode to the second mode. An exemplary communications device in accordance with some embodiments supports multiple peer discovery modes including a first receive peer discovery mode during which peer discovery signals are monitored at a first rate and a second receive peer discovery mode during which peer discovery signals are monitored at a second rate, said second rate being higher than the first rate, and device comprises: a first transition condition detection module for determining if a change condition used to trigger a change from the first mode to the second mode occurred when said communications device is operating in said first mode; and a first mode transition control module for controlling said communications device to transition from the first mode to the second mode when said first transition condition detection module detects that said change condition used to trigger a change from the first mode to the second mode has occurred. 
     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 communications device, e.g., a wireless terminal, to communicate discovery information. 
         FIG. 12 , comprising the combination of  FIG. 12A  and  FIG. 12B , is a flowchart of an exemplary method of operating a wireless terminal, e.g., a mobile node supporting peer to peer communications, to communicate discovery information, in accordance with an exemplary embodiment. 
         FIG. 13  is a drawing of an exemplary wireless terminal, e.g., peer to peer mobile node, which transmits discovery information portions 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 at different rates. 
         FIG. 15 , comprising the combination of  FIG. 15A  and  FIG. 15B , is a flowchart of an exemplary method of operating a communication device in accordance with an exemplary embodiment. 
         FIG. 16  is a drawing of an exemplary communications device, e.g., a peer to peer mobile wireless terminal, which supports a first transmit peer discovery mode and a second transmit peer discovery mode in accordance with an exemplary embodiment. 
         FIG. 17 , comprising the combination of  FIG. 17A  and  FIG. 17B , is a flowchart of an exemplary method of operating a communication device in accordance with an exemplary embodiment. 
         FIG. 18  is a drawing of an exemplary communications device, e.g., a peer to peer mobile wireless terminal, which supports a first receive peer discovery mode and a second receive peer discovery mode in accordance with an exemplary embodiment. 
         FIG. 19  is a drawing illustrating exemplary operations in a communications device supporting a high rate peer discovery transmit mode and a low rate peer discovery transmit mode in accordance with an exemplary embodiment. 
         FIG. 20  is a drawing illustrating exemplary operations in a communications device supporting a high rate peer discovery receive mode and a low rate peer discovery receive mode in accordance with an exemplary embodiment. 
         FIG. 21  is another drawing illustrating exemplary nodes in a peer to peer communications system and the transmission of discovery information at different rates. 
     
    
    
     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 fro 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 (P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 ), 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 (P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 , P 0 , P 1 , P 2 , P 3 ), 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 communications device, e.g. a wireless terminal, to communicate discovery information, e.g., to broadcast peer discovery information. Operation starts in step  1102  and proceeds to step  1104 . In step  1104 , the communications device stores information defining a peer discovery transmission structure, said structure indicating a plurality of ordered transmission units available for transmitting peer discovery information, said stored information including information indicating transmission units to be used for low rate discovery transmissions and additional transmission units to be used for high rate discovery transmissions, said information indicating more transmission units for high rate discovery transmissions than for low rate discovery transmissions. For example, in some exemplary embodiments, there are 4 additional transmission units for each low rate discovery transmission unit in the peer discovery transmission structure. See  FIG. 5 . Other peer discovery structures may have different ratios between the number of additional transmission units associated with high rate discovery and the number of number of transmission units associated with low rate discovery. Operation proceeds from step  1104  to step  1106 . 
     In step  1106 , the communications device transmits a first portion of a set of peer discovery information using a transmission unit corresponding to said low rate discovery transmissions. In some embodiments, the set of peer discovery information including the first portion includes a total of K portions, where K is a positive integer greater than or equal to 2. In some examples there are 4 portions in a set of peer discovery information. For example one set of 4 is the set {portion A N , portion B N , portion C N , portion D N }. Operation proceeds from step  1106  to step  1108 . 
     In step  1108 , the communications device transmits portion of a set of peer discovery information using a transmission unit corresponding to said high rate discovery transmissions. In some embodiments, the transmitted portion of step  1108  is a previously transmitted portion. The repeating of previously portions has benefits relating to security in combination with proxying. In some embodiments, the transmitted portion of step  1108  is not a previously transmitted portion. Operation proceeds from step  1108  to step  1110 . 
     In step  1110  the communications device transmits K−1 additional portions of peer discovery information using transmission units corresponding to high rate discovery transmissions. Operation proceeds from step  1110  to step  1112   
     Then, in step  1112 , the communications device transmits another portion of peer discovery information using another transmission unit corresponding to said low rate discovery transmissions. 
     A first example in accordance with the method of flowchart  1100  will now be described. In a first example, consider  FIG. 9 , and assume that the communications device stores peer discovery transmission structure information in accordance with the pattern of  FIG. 9  (step  1104 ). Also assume that the communications device is in a high rate discovery transmit mode and is transmitting using each of the illustrated discovery transmission units indicated in  FIG. 9 . The first portion transmitted in step  1106  is, e.g., portion A N  in the set of {A N , B N , C N , D N } and is transmitted using the low rate discovery transmission resource indicated by arrow  944 . In this example assume that a set of discovery information has K portions, where K=4. The previously transmitted portion transmitted in step  1108  is, e.g., portion B N-1 , which belongs to the set of {A N-1 , B N-1 , C N-1 , D N-1 } and is transmitted using the high rate discovery transmission resource indicated by arrow  946 . In this example, the previously transmitted portion of step  1108  corresponds to different set of peer discovery information than the set which includes the first portion of step  1106 . Continuing with the example, the K−1 additional portions transmitted in step  1110  are, e.g., the three portions C N-1 , D N-1 , A N  transmitted using transmission units corresponding to high rate discovery transmissions as indicated by arrows  948 ,  950 , and  952 . Continuing with the example, the another portion transmitted in step  1112  is, e.g., portion B N  which is transmitted using another transmission unit corresponding to low rate discovery transmissions as indicated by arrow  954 . 
     A second example in accordance with the method of flowchart  1100  will now be described. In the second example, consider  FIG. 9 , and assume that the communications device stores peer discovery transmission structure information in accordance with the pattern of  FIG. 9  (step  1104 ). Also assume that the communications device is in a high rate discovery transmit mode and is transmitting using each of the illustrated discovery transmission units indicated in  FIG. 9 . The first portion transmitted in step  1106  is, e.g., portion D N-1  in the set of {A N-1 , B N-1 , C N-1 , D N-1 } and is transmitted using the low rate discovery transmission resource indicated by arrow  934 . In this example assume that a set of discovery information has K portions, where K=4. The previously transmitted portion transmitted in step  1108  is, e.g., portion A N-1 , which belongs to the set of {A N-1 , B N-1 , C N-1 , D N-1 } and is transmitted using the high rate discovery transmission resource indicated by arrow  936 . In this example, the previously transmitted portion of step  1108  corresponds to the same set of peer discovery information as the set which includes the first portion of step  1106 . Continuing with the example, the K−1 additional portions transmitted in step  1110  are, e.g., the three portions B N-1 , C N-1 , D N-1  transmitted using transmission units corresponding to high rate discovery transmissions as indicated by arrows  938 ,  940 , and  942 . In this example, the first portion, the previously transmitted portion and the K−1 additional portions are all from the same set of peer discovery information. Continuing with the example, the another portion transmitted in step  1112  is, e.g., portion A N  which is transmitted using another transmission unit corresponding to low rate discovery transmissions as indicated by arrow  944 . 
     A third example in accordance with the method of flowchart  1100  will now be described. In the third example, consider  FIG. 10 , and assume that the communications device stores peer discovery transmission structure information in accordance with the pattern of  FIG. 10  (step  1104 ). Also assume that the communications device is in a high rate discovery transmit mode and is transmitting using each of the illustrated discovery transmission units indicated in  FIG. 10 . The first portion transmitted in step  1106  is, e.g., portion A N  in the set of {A N , B N , C N , D N } and is transmitted using the low rate discovery transmission resource indicated by arrow  1044 . In this example assume that a set of discovery information has K portions, where K=4. The previously transmitted portion transmitted in step  1108  is, e.g., portion B N-1 , which belongs to the set of {A N-1 , B N-1 , C N-1 , D N-1 } and is transmitted using the high rate discovery transmission resource indicated by arrow  1046 . In this example, the previously transmitted portion of step  1108  corresponds to a different set of peer discovery information as the set which includes the first portion of step  1106 . Continuing with the example, the K−1 additional portions transmitted in step  1110  are, e.g., the three portions C N-1 , D N-1 , A N-1  transmitted using transmission units corresponding to high rate discovery transmissions as indicated by arrows  1048 ,  1050 , and  1052 . In this example, the previously transmitted portion and the K−1 additional portions are all from the same set of peer discovery information. In addition, said previously transmitted portion and said N−1 additional portions are transmitted consecutively using transmission units corresponding to high rate peer discovery transmissions following transmission of said first portion. Continuing with the example, the another portion transmitted in step  1112  is, e.g., portion B N  which is transmitted using another transmission unit corresponding to low rate discovery transmissions as indicated by arrow  1054 . 
     A fourth example in accordance with the flowchart  1100  of  FIG. 11  will now be described. Multiple peer discovery related advertisements are sent with some being communicated at a low rate using low rate peer discovery transmissions and some being sent at a high rate using high rate peer discovery transmission. For example, a first peer discovery related advertisement is communicated at a low rate using the transmission of steps  1106  and  1112 , while a second peer discovery related advertisement is communicated using the transmissions of steps  1108  and  1110 . 
       FIG. 12 , comprising the combination of  FIG. 12A  and  FIG. 12B , is a flowchart  1200  of an exemplary method of operating a wireless terminal, e.g., a mobile node supporting peer to peer communications, to communicate discovery information, in accordance with an exemplary embodiment. The wireless terminal is, e.g., one of the peer to peer communications devices ( 102 ,  104 ,  106 ,  108 ,  110 ) of system  100  of  FIG. 1 . 
     The exemplary method of flowchart  1200  starts in step  1202  and proceeds to step  1204 , in which the wireless terminal stores peer to peer timing/frequency structure information as stored recurring peer to peer timing/frequency structure information  1206 . The storing of step  1204  is, e.g., part of a wireless terminal configuration and/or wireless terminal initialization process. The stored peer to peer timing/frequency structure information  1206  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 discovery interval pattern. The stored recurring peer to peer timing/frequency structure information  1206  defines a peer discovery transmission structure, which includes a plurality of ordered transmission units available for transmitting peer discovery information. Information  1206  includes information indicating transmission units to be used for low rate discovery transmissions and additional transmission units to be used for high rate discovery transmissions, and indicates that more transmission units for high rate discovery transmissions than for low rate discovery transmissions. Information described in  FIGS. 2 ,  3 ,  4 ,  5 ,  9  and/or  10  includes information that may be included as part of stored recurring peer to peer timing/frequency structure information. 
     Operation proceeds from step  1204  to step  1208 , in which the wireless terminal receives a reference signal. For example, the wireless receives a beacon signal, e.g., an OFDM beacon signal, from beacon transmitter  116  of  FIG. 1 , wherein the beacon signal is used to coordinate timing with respect to a peer to peer timing structure being used in system  100 . Operation proceeds from step  1208  to step  1210 . In step  1210 , the wireless terminal determines time with respect to the timing structure based on the received signal of step  1208 . Operation proceeds from step  1210  to steps  1212  and  1216 . 
     In step  1212 , which is performed on an ongoing basis, the wireless terminal maintains timing and outputs current time  1214 , which is utilized in other steps. Returning to step  1216 , in step  1216  the wireless terminal checks and determines whether it holds a device ID associated with discovery interval air link resources. If it does not currently hold a device ID associated with discovery interval air link resources, then operation returns to the input of step  1216 , for another check at a later point in time. However, if the wireless terminal does hold a device ID associated with discovery interval resources, then operation proceeds from step  1216  to step  1218  and step  1240 , via connecting node B  1220 . 
     Returning to step  1218 , in step  1218  the wireless terminal processes discovery information  1222 , using current time information  1214 , to create discovery interval transmission portions.  FIGS. 6 and 7  illustrate exemplary processing of discovery information and the generation of discovery interval transmission portions. Operation proceeds from step  1218  to step  1224 , in which the wireless terminal stores discovery interval portions with time tag information as part of stored discovery information sets information  1228 . An example of the output from step  1224  is presented for one set of information which includes stored discovery information transmission portion A  1230 , stored discovery information transmission portion B  1232 , stored discovery information portion C  1234 , stored discovery information portion D  1236 , and stored time tag information  1238 . In other embodiments, a different number of portions may correspond to a set of discovery information. In some embodiments, time tag information is not stored directly with a set of discovery information, but rather indirectly, e.g., with a set of discovery information being stored in a set of memory locations which the wireless terminal associates with an index value, e.g., set N−2, set N−1, set N. 
     Returning to step  1240 , in step  1240 , which is performed on a recurring basis, the wireless terminal identifies, using stored recurring peer to peer timing/frequency structure information  1206  and current time information  1214 , a discovery interval resource associated with the device ID currently being held by the wireless terminal. For each identified discovery interval resource associated with the device identifier being currently held by the wireless terminal, operation proceeds from step  1240  to step  1242 . In step  1242 , the wireless terminal determines the interval resource type of the identified discovery interval resource. If the identified interval resource is determined to be a low rate interval resource, then operation proceeds from step  1242  to step  1244 . However, if the wireless terminal determines that the identified interval resource is an additional interval resource, then operation proceeds from step  1242  to step  1246 . 
     Returning to step  1244 , in step  1244  the wireless terminal identifies a stored discovery interval portion to be transmitted. Inputs to step  1244  include stored recurring peer to peer timing/frequency structure information  1206  and discovery information sets including discovery information portions  1228 . Operation proceeds from step  1244  to step  1252 . In step  1252  the wireless terminal generates a signal conveying the identified stored discovery interval portion to be transmitted from step  1244 . Then, in step  1254  the wireless terminal transmits the generated signal conveying the identified discovery interval portion in accordance with the peer to peer timing structure during the discovery interval using the air link resource, e.g., segment, dedicated to the device ID currently being held by the wireless terminal. 
     Returning to step  1246 , in step  1246  the wireless terminal determines the wireless terminal mode of operation with regard to transmitting discovery information. If the wireless terminal is in low rate discovery transmit mode, then operation proceeds from step  1246  to step  1248 , where the device is controlled to refrain from transmitting during the discovery interval. However, if the device is in high rate discovery transmit mode, then operation proceeds from step  1246  to step  1250 . In step  1250 , the wireless terminal identifies a stored discovery interval portion to be transmitted. In some embodiments, the identified portion is a previously transmitted portion. Stored recurring peer to peer timing/frequency structure information  1206  and discovery information sets including discovery information portions  1228  are inputs to step  1250 . 
     Operation proceeds from step  1250  to step  1256 . In step  1256  the wireless terminal generates a signal conveying the identified stored discovery interval portion to be transmitted from step  1250 . Then in step  1258 , the wireless terminal transmits the generated signal conveying the identified discovery interval portion from step  1250  in accordance with the peer to peer timing/frequency structure during the discovery interval using the air link resource, e.g., segment, dedicated to the device ID being held by the wireless terminal. 
     In some embodiments, when in high rate discovery transmit mode, the wireless terminal executes  1  iteration of steps  1244 ,  1252  and  1254  for K iterations of steps  1250 ,  1256  and  1258 . For example, in one exemplary embodiment where discovery information in generated in sets of 4 portions, there is 1 iteration of step  1244 ,  1252  and  1254  corresponding to 4 iterations of steps  1250 ,  1256  and  1258 . 
     In some embodiments, e.g., embodiments supporting proxying techniques, discovery information portions are communicated using additional interval resources. For example, a discovery interval portion communicated in step  1258  may, and in some embodiments is, a discovery interval portion which has been previously transmitted in a low rate interval resource in step  1254 . 
     In some other embodiments, different discovery interval portions are communicated when transmitting using a low rate interval resource than when using an additional interval resource. For example a first set of discovery information is communicated using low rate discovery interval resources via the transmissions of multiple iterations of step  1254 , and a second set of discovery information is communicated using the additional discovery interval resources via the transmissions of multiple iterations of step  1258 . In one such embodiment there are more iterations of step  1258  than step  1254  for a given time interval. 
       FIG. 13  is a drawing of an exemplary wireless terminal  1300 , e.g., a peer to peer mobile node which transmits discovery information, in accordance with an exemplary embodiment. Wireless terminal  1300  is, e.g., one of the peer to peer communications devices ( 102 ,  104 ,  106 ,  108 ,  110 ) of system  100  of  FIG. 1 . Exemplary wireless terminal  1300  includes a wireless receiver module  1302 , a wireless transmitter module  1304 , user I/O devices  1308 , a processor  1306 , a memory  1310  coupled together via a bus  1312  over which the various elements may interchange data and information. In some embodiments, wireless terminal  1300  also include network interface  1307  for coupling the wireless terminal 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 wireless terminal  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 wireless terminal  1300  receives a timing reference signal, e.g., a beacon signal, used to synchronize to a peer to peer timing structure. Wireless receiver module  1302  also receives discovery information signals conveying discovery information portions from other wireless terminals which are the source of discovery information and/or from other nodes, e.g., assist nodes and/or server nodes which are assisting peer discovery by retransmitting portions of low rate peer discovery information. 
     Wireless transmitter module  1304 , e.g., an OFDM or CDMA transmitter, is coupled to transmit antenna  1316  via which the wireless terminal  1300  transmits discovery signals. In low rate discovery transmit mode the wireless terminal  1300  transmits discovery information portions during low rate discovery intervals using low rate discovery interval transmission units associated with an identifier that it currently holds, while it refrains from transmitting discovery information portions during additional discovery intervals associated with the identifier that it currently holds. In high rate discovery mode the wireless terminal  1300  transmits discovery signal portions during the low rate discovery intervals using low rate discovery interval transmission units associated with the identifier that it currently holds and transmits discovery signal portions during the additional discovery intervals using the additional discovery interval transmission units associated with the identifier that it currently holds. 
     User I/O devices  1308  include, e.g., a microphone, keyboard, keypad, switches, camera, speaker, display, etc. User I/O devices  1308  allow a user of wireless terminal  1300  to input data/information, access output data/information, and control at least some functions of the wireless terminal, e.g., initiate the broadcasting of one or more types of discovery information. Network interface  1307 , where included, allows the wireless terminal  1300  to be coupled to other network nodes and/or the Internet via a backhaul network. 
     Routines  1318  include a communications routine  1322  and control routines  1324 . The communications routine  1322  implements the various communications protocols used by the wireless terminal  1300 . The control routines  1324  include a low rate control module  1326 , a high rate control module  1328 , a timing structure storage module  1330 , a timing synchronization module  1332 , a timing maintenance module  1334 , a device ID module  1336 , a discovery information processing module  1338 , a discovery information portion storage module  1340 , a discovery interval identification module  1342 , a interval type determination module  1344 , a mode determination module  1346 , a low rate interval portion identification module  1348 , an additional interval portion identification module  1350 , and a discovery signal generation module  1352 . 
     Data/information  1320  includes stored timing/frequency structure information  1354 , information identifying a currently held device identifier associated with discovery air link resources  1378 , current time information  1368 , discovery information to be communicated  1370 , stored discovery information sets  1380 , information identifying the current discovery information transmit mode  1372 , an identified portion to be transmitted  1374 , and a generated discovery signal  1376 . Stored discovery information sets  1380  includes a most recent discovery information set  1382 , e.g., set N, and older generated discovery information sets such older discovery information set  1384 , e.g., set N-L, where N and L are integers. Each set of generated discovery information to be transmitted includes multiple portions. In this exemplary embodiment, set  1380  includes 4 portions (discovery information TX portion A  1386 , discovery information TX portion B  1388 , discovery information TX portion C  1390 , discovery information TX portion D  1392 ). 
     The stored timing/frequency structure information  1354  includes a plurality of sets of information identifying peer discovery interval air link resources corresponding to different identifiers which may be temporarily associated with wireless terminal  1300  (information identifying peer discovery interval resources for device identifier ID  1   1356 , . . . , information identifying peer discovery interval resources for device identifier ID M  1358 ), and mapping pattern information  1367 . Information identifying peer discovery interval resources for device identifier ID  1   1356  includes information identifying low rate peer discovery interval transmission units associated with device ID  1   1360  and information identifying additional discovery interval transmission units associated with device ID  1   1362 . Similarly, information identifying peer discovery interval resources for device identifier ID M  1358  includes information identifying low rate peer discovery interval transmission units associated with device identifier M  1364  and information identifying additional discovery interval transmission units associated with device identifier M  1366 . Mapping pattern information  1367  includes information defining a mapping pattern of generated discovery portions to particular transmission units. Information described with respect to  FIGS. 2 ,  3 ,  4 ,  5 ,  9  and/or  10  includes exemplary information included as part of the timing/frequency structure information  1354 . 
     The stored timing/frequency structure information  1354  includes information defining a peer discovery transmission schedule, the structure indicating a plurality of ordered transmission units available for transmitting peer discovery information, the stored information including information indicating transmission units to be used for low rate discovery transmissions and additional transmission units to be used for high rate discovery transmissions, the stored information indicating more transmission units for high rate discovery transmissions than for low rate discovery transmissions. Information identifying low rate peer discovery interval transmission units  1360  identifies fewer transmission units, e.g., segments, than information identifying additional discovery interval transmission units  1362 . Similarly, information identifying low rate peer discovery interval transmission units  1364  identifies fewer transmission units, e.g., segments, than information identifying additional discovery interval transmission units  1366 . In one embodiment, the ratio between low rate peer discovery transmission units to additional transmission units is 1:4. See  FIG. 5 . 
     Low rate control module  1326  controls the wireless transmitter module  1304  to transmit a portion of peer discovery information in a set of peer discovery information using a transmission unit corresponding to a low rate discovery transmission. For example, consider that wireless terminal  1300  currently holds device identifier ID M, low rate control module  1354  controls the wireless transmitter module  1304  to transmit a discovery portion during an interval identified by information  1364  using a transmission unit identified by information  1364 . 
     High rate control module  1328  controls the wireless transmitter module  1304  to transmit a previously transmitted portion of a set of peer discovery information using a transmission unit corresponding to high rate discovery transmissions. For example, consider that the wireless terminal  1300  currently holds device identifier ID M, high rate control module  1328  controls the wireless transmitter module  1304  to transmit a discovery portion during an interval identified by information  1366  using a transmission unit identified by information  1366 , wherein a discovery information portion transmitted during an additional discovery interval has been previously transmitted during a prior low rate discovery interval. 
     Timing structure storage module  1330  stores information defining a peer discovery transmission structure, e.g., a recurring timing/frequency structure. In some embodiments, the storage is part of a device configuration operation and/or device initialization operation. Stored timing/frequency structure information  1354  represents an output of module  1330 . The stored timing structure information  1354  includes information indicating a plurality of ordered transmission units available for transmitting peer discovery information, the stored information including information indicating transmission units to be used for low rate discovery transmissions and additional transmission units to be used for high rate discovery transmissions, the stored information indicating more transmission units for high rate discovery transmission than for low rate discovery transmissions. 
     Timing synchronization module  1332  synchronizes internal timing within wireless terminal  1300  with respect to an external reference, e.g., a received beacon signal, such that wireless terminal  1300  has its timing within the peer to peer recurring timing structure coordinated with respect to other peer to peer devices in the vicinity. Timing maintenance module  1334  maintains timing within wireless terminal  1300  on an ongoing basis, outputting current time information  1368 . 
     Device ID module  1336  performs functions including acquiring a device identifier associated with a set of discovery interval air link resources to be used temporarily by wireless terminal  1300 , determining whether or not wireless terminal  1300  currently holds such a device identifier, and relinquishing a currently held device identifier. 
     Discovery information processing module  1338  processes discovery information to be communicated  1370  to create discovery interval transmission portions. In some embodiments, the processing of module  1338  includes performing a secure hash function operation.  FIG. 6  and  FIG. 7  illustrate exemplary processing that may be performed by module  1338 . Discovery information portion storage module  1340  stores the processing outputs from module  1338  in stored discovery information sets  1380 . 
     Discovery information identification module  1342  determines whether or not a discovery interval air link resource in the recurring peer to peer timing/frequency structure is associated with a device identifier currently held by wireless terminal  1300 . Interval type determination module  1344  determines whether a discovery interval air link resource is a low rate peer discovery interval air link resource or an additional discovery interval air link resource. Mode determination module  1346  determines the current mode  1372  of wireless terminal  1300  with regard to the transmission of discovery information, e.g., (i) a low rate discovery information transmit mode in which the wireless terminal  1300  transmits discovery information portions using low rate peer discovery interval air link resources but does not use additional discovery interval air link resources or (ii) a high rate discovery information transmit mode in which the wireless terminal  1300  transmits discovery information portions using both low rate peer discovery interval air link resources and additional discovery interval air link resources. The discovery interval air link resources are sometimes referred to alternatively as discovery interval transmission units or discovery interval segments. 
     Low rate portion identification module  1348  identifies a stored discovery interval portion to be transmitted during a low rate peer discovery interval by wireless terminal  1300  from the stored discovery information  1380  in accordance with the stored timing/frequency structure information  1354 . Additional interval portion identification module  1350  identifies a stored discovery interval portion to be transmitted during an additional discovery interval by wireless terminal  1300  from the stored discovery information  1380  in accordance with the stored timing/frequency structure information  1354 . A portion identified to be transmitted during an additional discovery interval is a portion which has been previously transmitted during a prior low rate peer discovery interval. Identified portion to be transmitted  1374  can be an output of either module  1348  or module  1350 , and it is an input to discovery signal generation module  1352 . Discovery signal generation module  1352  generates a discovery signal to convey an identified discovery interval portion to be transmitted. Generated discovery signal  1376  is an output of module  1352 . 
     Wireless transmitter module  1302  transmits portions of peer discovery information. The low rate control module  1326  controls the wireless transmitter module  1302  to transmit a first portion of a set of peer discovery information using a transmission unit corresponding to low rate discovery transmissions. The high rate control module  1328  controls the wireless transmitter module  1302  to transmit a portion of a set of peer discovery information using a transmission unit corresponding to high rate discovery transmissions, e.g., a previously transmitted portion of a set of peer discovery information. For some cases, the previously transmitted portion of a set of peer discovery information corresponds to a different set of peer discovery information than the set of peer discovery information which includes the first portion. For some other cases, the previously transmitted portion of a set of peer discovery information corresponds to the same set of peer discovery information as the first portion. The high rate control module  1328 , in some embodiments, controls the wireless transmitter module  1302  to transmit a previously transmitted portion following transmission of the first portion. At times, transmitting a previously transmitted portion precedes transmission of another portion of peer discovery information using another transmission unit corresponding to low rate discovery transmissions. 
     In various embodiments, the set of peer discovery information including the first portion includes a total of K portions, e.g., 4 portions. In some such embodiments, the wireless transmitter module  1302  is also for transmitting additional portions of peer discovery information in addition to said first portion and said previously transmitted portion. In some such embodiments, the high rate control module controls the wireless transmitter module  1302  to transmit K−1 additional portions of peer discovery information using transmission units corresponding to high rate discovery transmissions following transmission of said first portion and prior to transmission of said another portion. For example, consider that K=4. The wireless terminal  1300  transmits in order: (i) the first portion using a first low rate discovery transmission unit; (ii) a previously transmitted discovery portion using a first additional transmission unit associated with high rate transmissions; (iii) a second previously transmitted discovery portion using a second additional transmission unit associated with high rate transmissions; (iv) a third previously transmitted discovery portion associated with high rate transmissions; (v) a fourth previously transmitted discovery portion associated with high rate transmissions; and (vi) a second portion using a second low rate discovery transmission unit. The transmission sequence is such that during some times, the first portion transmitted using a low rate discovery transmission unit and the K−1 discovery portions using high rate discovery transmission units are all from the same set of peer discovery information. 
     In some embodiments, the previously transmitted portion and the K−1 additional portions are controlled to be transmitted consecutively using transmission units corresponding to high rate peer discovery transmissions following transmission of the first portion using a low rate discovery transmission unit. For some embodiments, the previously transmitted portion and the K−1 additional portions are all from the same set of peer discovery information. Refer to the example of  FIG. 10 . In some other embodiments, during some intervals of the recurring structure, the previously transmitted portion and the K−1 additional portions are all from the same set of peer discovery information, while during some other intervals in the recurring structure the previously transmitted portion and the K−1 additional portions include members from two different sets of discovery information. Refer to  FIG. 9 . 
       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 are, e.g., any of the peer to peer communications devices ( 102 ,  104 ,  106 ,  108 ,  110 ) of  FIG. 1 . 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 . The exemplary nodes also include a third wireless terminal  1406 , e.g., a third peer to peer mobile node, which is operating during a first time in a high rate discovery mode and is transmitting discovery information at a high rate, but then changes to operate in a low rate discovery mode and transmits discovery information at a low rate, as indicated by discovery signals  1416  being transmitted along time axis  1410 . In some embodiments, at least some of the wireless terminals perform discovery information transmissions in one mode but not the other. In some embodiments, at least some of the wireless terminals are multi-mode with regard to the transmission of discovery information, e.g., transmitting at high rate at some times while transmitting at a low rate at other times. 
       FIG. 15 , comprising the combination of  FIG. 15A  and  FIG. 15B , is a flowchart  1500  of an exemplary method of operating a communication device in accordance with an exemplary embodiment. The communications device, e.g., a peer to peer communications device, supports multiple peer discovery modes including a first transmit peer discovery mode during which discovery signals are transmitted at a first rate and a second transmit peer discovery mode during which discovery signals are transmitted at a second rate, said second rate being higher than said first rate. 
     Operation starts in step  1502 , where the communications device is powered on and initialized. Initialization of start step  1502  may, and sometimes does, include setting the communications device in one of the first transmit peer discovery mode and the second transmit peer discovery mode. Operation proceeds from start step  1502  to step  1504 . In step  1504 , the communications device determines whether the communications device is in the first or second peer discovery transmit mode and proceeds accordingly. If the communications device is in the first peer discovery transmit mode, operation proceeds from step  1504  to step  1506 . However, if the communications device is in the second peer discovery transmit mode, then operation proceeds from step  1504  via connecting node A  1526  to step  1528 . 
     Returning to step  1506 , in step  1506  the communications device determines if a change conditions used to a trigger a transition from the first transmit peer discovery mode to the second transmit peer discovery mode has occurred. Step  1506  includes one or more of sub-steps  1508  and  1510 . 
     In sub-step  1508  the communications device makes the determination as a function of received peer discovery signals. Sub-step  1508  includes one or more of sub-steps  1512 ,  1514 ,  1516 , and  1518 . In sub-step  1512 , the communications device determines if a peer discovery signal has been received from a device from which a peer discovery signal was not previously received within a predetermined period of time. In sub-step  1514 , the communications device makes the determination as a function of the number of newly discovered devices, said number of newly discovered devices being a number of devices from which peer discovery signals are received during a second predetermined time interval but excluding devices from which peer discovery signals were received in a first predetermined period of time prior to the determination. For example, a detected high rate of change of received peer discovery information may indicate a rapidly changing environment, and the communications device may be triggered to switch into high rate transmit mode so that others will be able to detect its presence. The device may desire it advertise its presence at a high rate for at least an interval of time since an increasing number of new devices are present in the area. In sub-step  1516 , the communications device determines when the number of different devices from which peer discovery signals are received in a time interval exceeds a threshold number. For example, the device may wait until a minimum number of devices, e.g., devices of interest, have been detected by it in its vicinity before it decides to switch to a high rate mode. In sub-step  1518 , the communications device determines if a peer discovery signal includes information indicating that the peer device from which the peer discovery signal was received belongs to a group of devices of interest to the communications device. Thus the communications device may be triggered to transition into a high rate when it detects the presence of a relevant peer. In some embodiments, sub-step  1518  includes sub-step  1520 , in which the communications device makes a probabilistic determination. In some embodiments, the probabilistic determination is a determination based on a portion of an ID. For example, a partial match may trigger a transition into the high rate transmit mode. In various embodiments, the device in said group include at least one of the following: i) a device corresponding to an entry in a buddy list stored in said communications device; ii) a device that provides a service available to said communications device; and iii) a device that implements an application identified in information stored in said communications device. Entries on the buddy list are, e.g., family members, friends, business associates, member of a club or group, members of an organization, etc. 
     Returning to sub-step  1510 , in sub-step  1510 , the communications device makes the determination as a function of one of: i) a change in a set of active applications, ii) a change to an active application, and iii) user input. A change to a set of active application may include a new or dormant application being started, and it may be desirable to switch to high rate peer discovery transmit mode to execute the application and communicate with other devices promptly and/or more efficiently. Exemplary changes to active applications include a mode change of an application, a configuration change of an application, and a parameter setting change of an application. 
     Operation proceeds from step  1506  to step  1522 . In step  1522  the communications device proceeds based on the determination of step  1506 . If the determination of step  1506  is that a change condition used to trigger a change from the first transmit peer discovery mode to the second transmit peer discovery mode has not occurred, then operation proceeds from step  1522  to the input of step  1506 . However if the determination of step  1506  is that a change condition used to trigger a change from the first transmit peer discovery mode to the second transmit peer discovery mode has occurred, then operation proceeds from step  1522  to step  1524 . In step  1524  the communications device transitions from the first transmit peer discovery mode to the second transmit peer discovery mode. Operation proceeds from step  1524  to step  1504 . 
     Returning to step  1528 , in step  1528  the communications device determines if a change condition used to trigger a transition from the second transmit peer discovery mode to the first transmit peer discovery mode has occurred. Step  1528  includes one or more of sub-steps  1530 ,  1532 ,  1534  and  1535 . In sub-step  1530  the communications device determines if a timer has expired indicating passing of a time from the most recent time a condition used to trigger a transition from the first peer discovery transmit rate and/or the first transmit peer discovery mode to the second peer discovery transmit rate and/or second transmit peer discovery mode was detected. In sub-step  1532  the communications device makes the determination as a function of received peer discovery signals. In some such embodiments, sub-step  1532  includes one or more of sub-step  1536  and  1538 . In sub-step  1536  the communications device makes the determination as a function of the number of newly discovered devices, said number of newly discovered devices being a number of devices from which discovery signals are being received during a fourth predetermined time period but excluding device from which peer discovery signals were received in a third predetermined period of time prior to said determination. For example, if the number of newly discovered devices falls off, it may indicate stabilization in the area, and the device may decide to slow down its rate of transmitting peer discovery information and thus switch back to the first mode. In sub-step  1538 , the communications device determines when the number of different devices from which peer discovery signals are received in a time interval is below a threshold number. For example, the communications device may decide that the number of devices remaining in its vicinity has fallen off to a level that does not justify its expenditure of its resources, e.g., battery power, to keep transmitting discovery information at a high rate and thus it triggers a transition back to the first mode where it will transmit at a lower rate. In sub-step  1534 , the communications device determines whether or not a peer device which was determined to probabilistically belong to a group of devices of interest is not a member of said group of devices of interest. For example, the device may have been transitioned to the second mode based on a partial match in step  1518  and  1520 , and additional received discovery information subsequently received indicates that a match does not exist; therefore, the device may be triggered to transition back to the first mode. In sub-step  1535  the communications device makes the determination as a function of change in battery status. For example, a detected change in monitored battery status indicating a low battery condition can be, and sometimes is, used to trigger a change from the second transmit mode to the first transmit mode, thereby conserving the remaining battery power and facilitating longer operating time of the communications device before needing a battery recharge. 
     Operation proceeds from step  1528  to step  1540 . In step  1540  the communications device proceeds depending upon the determination of step  1528 . If the determination of step  1528  is that a change condition used to trigger a change from the second transmit peer discovery mode to the first transmit peer discovery mode has not occurred, then the device remains in the second transmit peer discovery mode, and operation proceeds from step  1540  to the input of step  1528 . However, if the determination of step  1528  is that a change condition used to trigger a change from the second transmit peer discovery mode to the first transmit peer discovery mode has occurred, then operation proceeds from step  1540  to step  1542 . In step  1542  the communications device transitions from the second transmit peer discovery mode to the first transmit peer discovery mode. Operation proceeds from step  1542  to step  1504 , via connecting node B  1544 . 
       FIG. 16  is a drawing of an exemplary communications device  1600 , e.g., a peer to peer mobile wireless terminal, in accordance with an exemplary embodiment. Exemplary communications device  1600  supports multiple peer discovery modes including a first transmit peer discovery mode during which peer discovery signals are transmitted at a first rate and a second peer discovery mode during which peer discovery signals are transmitted at a second rate, said second rate being higher than said first rate. 
     Communications device  1600  includes a wireless receiver module  1602 , a wireless transmitter module  1604 , a processor  1606 , user I/O devices  1608 , a memory  1610  and a battery  1612  coupled together via a bus  1614 , via which the various elements may interchange data/information. Power distribution and power monitoring is also via bus  1614 . Bus  1614  includes a power portion and a data/information portion. In some embodiments communications device  1600  also includes network interface  1616  which is also coupled to bus  1614 . The network interface  1616 , when included, can be used to couple the communications device  1600  to other network nodes and/or the Internet, e.g., via a backhaul. 
     Memory  1610  includes routines  1622  and data/information  1624 . The processor  1606 , e.g., a CPU, executes the routines  1622  and uses the data/information  1624  in memory  1610  to control the operation of the communications device  1600  and implement methods, e.g., the method of flowchart  1500  of  FIG. 15 . 
     Wireless receiver module  1602 , e.g., an OFDM or CDMA receiver, is coupled to receive antenna  1618  via which the communications device  1600  receives signals from other communications devices, e.g., discovery signals from other peer to peer communications devices. Wireless transmitter module  1604 , e.g., an OFDM or CDMA transmitter, is coupled to transmit antenna  1620  via which the communications device transmits signals to other communications devices. Transmitted signals include, e.g., discovery information signals. Discovery information signals can be broadcast at different rates, e.g., a low rate while in a first transmit peer discovery mode and a high rate while in a second transmit peer discovery mode. In some embodiments, the same antenna is used for transmitter and receiver. 
     User I/O devices  1608  include, e.g., a microphone, a keyboard, a keypad, switches, a camera, a speaker, a display, etc. User I/O devices  1608  allow an operator of communications device  1600  to input user data, access output user data and control at least some functions of the communications device, e.g., select a peer discovery transmit mode of operation. 
     Battery  1612  provides a power source for communications device  1600 . Battery status is monitored and the transmit peer discovery mode of operation can be, and sometimes is, changed as a function of battery status. 
     Routines  1622  includes a communications routine  1626  and control routines  1628 . Communications routine  1626  implements the various communications protocols used by the communications device  1600 . Control routines  1628  include a first transition condition detection module  1630 , a first mode transition control module  1632 , a new device detection module  1634 , a first newly discovered device counting module  1636 , an assembly determination module  1638 , an affiliation determination module  1640 , an active application set tracking module  1649 , an active application change module  1650 , a user input module  1651 , a second transition condition detection module  1652 , a second mode transition control module  1654 , a timer module  1656 , a timer expiration module  1658 , a second newly discovered device counting module  1660 , an assembly dispersion determination module  1662 , a false identification determination module  1664 , a battery monitoring module  1666 , and a peer discovery signal generation module  1668 . Affiliation determination module  1640  includes a probabilistic determination module  1642 , a buddy detection sub-module  1644 , a service detection sub-module  1646  and an application detection sub-module  1648 . 
     Data/information  1624  includes received peer discovery signals  1670 , a buddy list  1672 , an application list  1674 , a service availability list  1676 , received user input  1678 , 1 st  predetermined time interval information  1680 , 2 nd  predetermined time interval information  1682 , 3 rd  predetermined time interval information  1684 , 4 th  predetermined time interval information  1686 , a current mode of operation  1688 , timing frequency structure information  1690  and generated peer discovery signals for transmission  1696 . The timing/frequency structure information  1690  includes first transmit mode peer discovery air link resources information  1692  and second transmit peer discovery mode air link resources information  1694 . 
     First transition condition detection module  1630  determines if a change condition used to trigger a change from the first transmit peer discovery mode to the second transmit peer discovery mode occurred when the communications device  1600  is operating the first transmit peer discovery mode. At times, first transition condition detection module  1630  makes the determination as a function of a received peer discovery signal. Sometimes, the first transition condition detection module  1630  makes the determination as a function of a plurality of received peer discovery signals. First mode transition control module  1632  controls the communications device  1600  to transition from the first transmit peer discovery mode to the second transmit peer discovery mode when the first transition condition detection module  1630  detects that the change condition used to trigger a change from the first transmit peer discovery mode to the second transmit peer discovery mode has occurred. 
     New device detection module  1634  determines if a peer discovery signal has been received from a device from which a peer discovery signal was not previously received within a predetermined period of time. First transition condition detection module  1630  can, and sometimes does, make a change condition determination as a function of a new device detection module  1634  determination. 
     First newly discovered device counting module  1636  determines a number of newly discovered devices, said number of newly discovered devices being a number of device from which peer discovery signals are received during a second predetermined time interval but excluding devices from which peer discovery signals were received in a first predetermined period of time prior to said determination if a change condition has occurred. First transition condition detection module  1630  can, and sometimes does, make a change condition determination as a function of the number of newly discovered devices as reported by module  1636 . 1 st  predetermined time interval information  1680  and 2 nd  predetermined time interval information  1682  are used by first newly discovered device counting module  1636  in determining a number of newly discovered devices. 
     Assembly determination module  1638  determines when the number of different devices from which peer discovery signals are received in a time interval exceeds a threshold number. First transition condition detection module  1630  can, and sometimes does, make a change condition determination as a function of an assembly determination module  1638  determination. 
     Affiliation determination module  1640  determines if a peer discovery signal includes information indicating that a peer device from which the peer discovery signal was received belongs to a group of devices of interest to the communications device  1600 . First transition condition detection module  1630  can, and sometimes does, make a change condition determination as a function of the affiliation determination module  1640  determination. 
     Probabilistic determination module  1642  makes a probabilistic determination as to whether a peer discovery signal includes information indicating that the peer device from which the peer discovery signal was received belongs to a group of devices of interest to the communications device. For example, one received per discovery signal may include a portion of a set of peer discovery information, and the probabilistic determination module  1642  can make a probabilistic determination based on the received portion of the set of discovery information, even though the complete set is unavailable at the current time to the communications device  1600 . In some embodiments, an identifier such as a device identifier carried in a discovery information signal conveys less than the full set of bits needed to perform a unique identification but may include a sufficient number of bits to perform a positive identification with an acceptable degree of certainty. For example, an abbreviated identifier may be communicated in a discovery information portion to save air link resources, with the understanding that false positive identifications may occasionally occur. In some embodiments, the probabilistic determination is a determination based on a portion of an ID. 
     Buddy detection sub-module  1644  uses buddy list  1672 , e.g., stored information identifying devices and/or users of devices designated as buddies of the communications device  1600 , to determine if a received peer discovery signal is from a device corresponding to an entry in the stored buddy list. 
     Service detection sub-module  1646  uses service availability list  1676 , e.g. stored information identifying services available to the communication device  1600 , to determine if a received peer discovery signal is from a device corresponding to an entry in said stored discovery availability list  1676 . 
     Application detection sub-module  1648  uses application list  1674 , e.g., stored information identifying applications of interest to the communications device  1600 , to determine if a received peer discovery signal is from a device corresponding to an entry in the stored application list  1674 . 
     Active application set tracking module  1649  determines if a change in a maintained set of application has occurred. First transition condition detection module  1630  can, and sometimes does, make a change condition determination as a function of the active application set tracking module  1649  determination. 
     Active application change module  1650  determines if a change to an active application has occurred. Exemplary changes to active applications include a mode change of an application, a configuration change of an application, and a parameter setting change of an application. First transition condition detection module  1630  can, and sometimes does, make a change condition determination as a function of the active application change module  1650  determination. 
     User input module  1651  receives input from a user of the communications device  1600  via a user I/O device included in user I/O devices  1608 , e.g., a user selection, request or command to change to the second peer discovery transmit mode. First transition condition detection module  1630  can, and sometimes does, make a change condition determination as a function received user input from the user input module  1651 . 
     Second transition condition detection module  1652  determines if a change condition used to trigger a change from the second transmit peer discovery mode to the first transmit peer discovery mode occurred when the communications device is operating the second transmit peer discovery mode. Second transition condition detection module  1652  at times makes the determination if a change condition used to trigger a change from the second transmit peer discovery mode to the first transmit peer discovery mode occurred as a function of a received peer discovery signal. Second mode transition control module  1654  controls the communications device to transition from the second transmit peer discovery mode to the first transmit peer discovery mode when the second condition detection module  1652  detects that a change condition used to trigger a change from the second transmit peer discovery mode to the first transmit peer discovery mode has occurred. 
     Timer module  1656  tracks the amount of time since the most recent time a condition used to trigger a transition from the first rate and/or first mode to the second rate and/or second mode was detected. Timer expiration module  1658  determines if the amount of time indicated by the timer module  1656  exceeds an expiration time. The second transition condition detection module  1652  can, and sometimes does, determine if a change condition used to trigger a change from the second transmit peer discovery mode to the first transmit peer discovery mode has occurred as a function of the timer expiration module  1658  determination. 
     Second newly discovered device counting module  1660  determines a number of newly discovered devices, said number of newly discovered devices being a number of devices from which peer discovery signals are received during a fourth predetermined time interval but excluding device from which peer discovery signals were received in a third predetermined period of time prior to said determination if a change condition has occurred. Third predetermined time interval information  1684  and fourth predetermined time interval information  1686  are used by module  1660  in obtaining a count. The second transition condition detection module  1652  can, and sometimes does, determine if a change condition used to trigger a change from the second transmit peer discovery mode to the first transmit peer discovery mode has occurred as a function of the number of newly discovered devices as annunciated by second newly discovered devices counting module  1660 . 
     Assembly dispersion determination module  1662  determines when the number of different devices from which peer discovery signals are received in a time interval is below a threshold number. The second transition condition detection module  1652  can, and sometimes does, determine if a change condition used to trigger a change from the second mode to the first mode has occurred as a function of the assembly dispersion determination module  1662  determination. 
     False identification determination module  1664  determines if a peer device which had been determined to probabilistically belong to a group of device of interest is not a member of the group of devices of interest. The second transition condition detection module  1652  can, and sometimes does, determine if a change condition used to trigger a change from the second transmit peer discovery mode to the first transmit peer discovery mode has occurred as a function of the false identification determination module  1664  determination. 
     Battery monitoring module  1666  monitors the amount of reserve battery power remaining in the battery  1612  and determines the current battery status condition. The second transition condition detection module  1652  can, and sometimes does, determine if a change condition used to trigger a change from the second mode to the first mode has occurred as a function of the battery monitoring module  1666  status determination. For example, in response to a low battery status indication the communications device is transitioned to the first transmit peer discovery mode so that power may be conserved and the device may operate for a longer time before a recharge is needed. 
     Peer discovery signal generation module  1668  generates peer discovery signals for transmission  1696 . Generated peer discovery signals are transmitted at a first rate when the current mode  1688  indicates that the communications device  1600  is currently operating in a first transmit peer discovery mode using air link resources, e.g., segments, identified by information  1692 . Generated peer discovery signals are transmitted at a second rate when the current mode  1688  indicates that the communications device  1600  is currently operating in a second transmit peer discovery mode using air link resources, e.g., segments, identified by information  1694 . 
       FIG. 17 , comprising the combination of  FIG. 17A  and  FIG. 17B , is a flowchart  1700  of an exemplary method of operating a communication device in accordance with an exemplary embodiment. The communications device, e.g., a peer to peer communications device, supports multiple peer discovery modes including a first receive peer discovery mode during which discovery signals are monitored at a first rate and a second receive peer discovery mode during which discovery signals are monitored at a second rate, said second rate being higher than said first rate. 
     Operation starts in step  1702 , where the communications device is powered on and initialized. Initialization of start step  1702  may, and sometimes does, include setting the communications device in one of the first receive peer discovery mode and the second receive peer discovery mode. Operation proceeds from start step  1702  to step  1704 . In step  1704 , the communications device determines whether the communications device is in the first or second receive peer discovery modes and proceeds accordingly. If the communications device is in the first receive peer discovery mode, operation proceeds from step  1704  to step  1706 . However, if the communications device is in the second receive peer discovery mode, then operation proceeds from step  1704  via connecting node A  1726  to step  1728 . 
     Returning to step  1706 , in step  1706  the communications device determines if a change conditions used to a trigger a transition from the first receive peer discovery mode to the second receive peer discovery mode has occurred. Step  1706  includes one or more of sub-steps  1708  and  1710 . 
     In sub-step  1708  the communications device makes the determination as a function of received peer discovery signals. Sub-step  1708  includes one or more of sub-steps  1712 ,  1714 ,  1716 , and  1718 . In sub-step  1712 , the communications device determines if a peer discovery signal has been received from a device from which a peer discovery signal was not previously received within a predetermined period of time. In sub-step  1714 , the communications device makes the determination as a function of the number of newly discovered devices, said number of newly discovered devices being a number of devices from which peer discovery signals are received during a second predetermined time interval but excluding devices from which peer discovery signals were received in a first predetermined period of time prior to the determination. In sub-step  1716 , the communications device determines when the number of different devices from which peer discovery signals are received in a time interval exceeds a threshold number. In sub-step  1718 , the communications device determines if a peer discovery signal includes information indicating that the peer device from which the peer discovery signal was received belongs to a group of devices of interest to the communications device. In some embodiments, sub-step  1718  includes sub-step  1720 , in which the communications device makes a probabilistic determination. In some embodiments, the probabilistic determination is a determination based on a portion of an ID. In various embodiments, the device in said group include at least one of the following: i) a device corresponding to an entry in a buddy list stored in said communications device; ii) a device that provides a service available to said communications device; and iii) a device that implements an application identified in information stored in said communications device. 
     Returning to sub-step  1710 , in sub-step  1710 , the communications device makes the determination as a function of one of: i) a change in a set of active applications, ii) a change to an active application, and iii) user input. Exemplary changes to active applications include a mode change of an application, a configuration change of an application, and a parameter setting change of an application. 
     Operation proceeds from step  1706  to step  1722 . In step  1722  the communications device proceeds based on the determination of step  1706 . If the determination of step  1706  is that a change condition used to trigger a change from the first receive peer discovery mode to the second receive peer discovery mode has not occurred, then operation proceeds from step  1722  to the input of step  1706 . However if the determination of step  1706  is that a change condition used to trigger a change from the first receive peer discovery mode to the second receive peer discovery mode has occurred, then operation proceeds from step  1722  to step  1724 . In step  1724  the communications device transitions from the first receive peer discovery mode to the second receive peer discovery mode. Operation proceeds from step  1724  to step  1704 . 
     Returning to step  1728 , in step  1728  the communications device determines if a change condition used to trigger a transition from the second receive peer discovery mode to the first receive peer discovery mode has occurred. Step  1728  includes one or more of sub-steps  1730 ,  1732 ,  1734  and  1735 . In sub-step  1730  the communications device determines if a timer has expired indicating passing of a time from the most recent time a condition used to trigger a transition from the first rate and/or first receive peer discovery mode to the second rate and/or second receive peer discovery mode was detected. In sub-step  1732  the communications device makes the determination as a function of received peer discovery signals. In some such embodiments, sub-step  1732  includes one or more of sub-step  1736  and  1738 . In sub-step  1736  the communications device makes the determination as a function of the number of newly discovered devices, said number of newly discovered devices being a number of devices from which discovery signals are being received during a fourth predetermined time period but excluding device from which peer discovery signals were received in a third predetermined period of time prior to said determination. In sub-step  1738 , the communications device determines when the number of different devices from which peer discovery signals are received in a time interval is below a threshold number. In sub-step  1734 , the communications device determines whether or not a peer device which was determined to probabilistically belong to a group of devices of interest is not a member of said group of devices of interest. In sub-step  1735  the communications device makes the determination as a function of change in battery status. For example, a detected change in monitored battery status indicating a low battery condition can be, and sometimes is, used to trigger a change from the second receive peer discovery mode to the first receive peer discovery mode, thereby conserving the remaining battery power and facilitating longer operating time of the communications device before needing a battery recharge. 
     Operation proceeds from step  1728  to step  1740 . In step  1740  the communications device proceeds depending upon the determination of step  1728 . If the determination of step  1728  is that a change condition used to trigger a change from the second receive peer discovery mode to the first receive peer discovery mode has not occurred, then the device remains in the second receive peer discovery mode, and operation proceeds from step  1740  to the input of step  1728 . However, if the determination of step  1728  is that a change condition used to trigger a change from the second receive peer discovery mode to the first receive peer discovery mode has occurred, then operation proceeds from step  1740  to step  1742 . In step  1742  the communications device transitions from the second receive peer discovery mode to the first receive peer discovery mode. Operation proceeds from step  1742  to step  1704 , via connecting node B  1744 . 
       FIG. 18  is a drawing of an exemplary communications device  1800 , e.g., a peer to peer mobile wireless terminal, in accordance with an exemplary embodiment. Exemplary communications device  1800  supports multiple peer discovery modes including a first receive peer discovery mode during which peer discovery signals are monitored at a first rate and a second receive peer discovery mode during which peer discovery signals are monitored at a second rate, said second rate being higher than said first rate. 
     Communications device  1800  includes a wireless receiver module  1802 , a wireless transmitter module  1804 , a processor  1806 , user I/O devices  1808 , a memory  1810  and a battery  1812  coupled together via a bus  1814 , via which the various elements may interchange data/information. Power distribution and power monitoring is also via bus  1814 . Bus  1814  includes a power portion and a data/information portion. In some embodiments communications device  1800  also includes network interface  1816  which is also coupled to bus  1814 . The network interface  1816 , when included, can be used to couple the communications device  1800  to other network nodes and/or the Internet, e.g., via a backhaul. 
     Memory  1810  includes routines  1822  and data/information  1824 . The processor  1806 , e.g., a CPU, executes the routines  1822  and uses the data/information  1824  in memory  1810  to control the operation of the communications device  1800  and implement methods, e.g., the method of flowchart  1700  of  FIG. 17 . 
     Wireless receiver module  1802 , e.g., an OFDM or CDMA receiver, is coupled to receive antenna  1818  via which the communications device  1800  receives signals from other communications devices, e.g., discovery signals from other peer to peer communications devices and peer to peer traffic signals from other communications devices. Discovery information signals can be monitored at different rates, e.g., a low rate while in a first receive peer discovery mode and a high rate while in a second receive peer discovery mode. Peer discovery information signals are received by wireless receiver module  1802  on air link resources, e.g., segments, identified by first receive peer discovery mode air link resources information  1892  when in the first receive mode of peer discovery operation. Peer discovery information signals are received by wireless receiver module  1802  on air link resources, e.g., segments, identified by second receive peer discovery mode air link resources information  1894  when in the second receive mode of peer discovery operation. 
     Note that the rate of reception of peer discovery information corresponding to the receive peer discovery mode of communications device  1800  need not be, and sometimes is not, the same as the rate of transmission from another peer discovery device sourcing signals received by communications device  1800 . In addition corresponding to a set of monitored discovery information air link resources associated with a particular device identifier, at times, some of the discovery information signals may be sourced from a peer to peer device while other discovery information signals may be sourced from a node functioning to provide discovery assistance. For example, in one case communications device  1800  is in the second receive peer discovery mode, e.g., high receive rate mode, another peer node sourcing peer discovery signals received by device  1800  is in a first transmit peer discovery mode, e.g., low transmit mode, and a peer discovery assist node, situated in the vicinity of device  1800  and the another peer node transmits peer discovery signals on the additional air link resources associated with the device identifier conveying peer discovery signals that would have been transmitted by the another peer node if it had been in the second transmit peer discovery mode of operation. 
     In another example, device  1800  is in a first, e.g., low rate, receive peer discovery mode, while another peer node transmitting peer discovery signals is in a second, e.g., high rate, transmit peer discovery mode, and device  1800  monitors discovery signals associated with low rate peer discovery air link resources but refrains from monitoring on the air link resources which are used in high rate discovery but not used in low rate discovery. 
     Wireless transmitter module  1804 , e.g., an OFDM or CDMA transmitter, is coupled to transmit antenna  1820  via which the communications device  1800  transmits signals to other communications devices. Transmitted signals include, e.g., discovery information signals and peer to peer traffic signals. In some embodiments, the same antenna is used for transmitter and receiver. 
     User I/O devices  1808  include, e.g., a microphone, a keyboard, a keypad, switches, a camera, a speaker, a display, etc. User I/O devices  1808  allow an operator of communications device  1800  to input user data, access output user data and control at least some functions of the communications device, e.g., select a peer discovery receive mode of operation. 
     Battery  1812  provides a power source for communications device  1800 . Battery status is monitored and the receive peer discovery mode of operation can be, and sometimes is, changed as a function of battery status. 
     Routines  1822  includes a communications routine  1826  and control routines  1828 . Communications routine  1826  implements the various communications protocols used by the communications device  1800 . Control routines  1828  include a first transition condition detection module  1830 , a first mode transition control module  1832 , a new device detection module  1834 , a first newly discovered device counting module  1836 , an assembly determination module  1838 , an affiliation determination module  1840 , an active application set tracking module  1849 , an active application change module  1850 , a user input module  1851 , a second transition condition detection module  1852 , a second mode transition control module  1854 , a timer module  1856 , a timer expiration module  1858 , a second newly discovered device counting module  1860 , an assembly dispersion determination module  1862 , a false identification determination module  1864 , and a battery monitoring module  1866 . 
     Affiliation determination module  1840  includes a probabilistic determination module  1842 , a buddy detection sub-module  1844 , a service detection sub-module  1846  and an application detection sub-module  1848 . 
     Data/information  1824  includes received peer discovery signals  1870 , a buddy list  1872 , an application list  1874 , a service availability list  1876 , received user input  1878 , 1 st  predetermined time interval information  1880 , 2 nd  predetermined time interval information  1882 , 3 rd  predetermined time interval information  1884 , 4 th  predetermined time interval information  1886 , a current mode of operation  1888 , and timing frequency structure information  1890 . The timing/frequency structure information  1890  includes first receive mode peer discovery air link resources information  1892  and second receive mode peer discovery mode air link resources information  1894 . 
     First transition condition detection module  1830  determines if a change condition used to trigger a change from the first receive peer discovery mode to the second receive peer discovery mode occurred when the communications device  1800  is operating the first receive peer discovery mode. At times, first transition condition detection module  1830  makes the determination as a function of a received peer discovery signal. Sometimes, the first transition condition detection module  1830  makes the determination as a function of a plurality of received peer discovery signals. First mode transition control module  1832  controls the communications device  1800  to transition from the first mode to the second mode when the first transition condition detection module  1830  detects that the change condition used to trigger a change from the first receive peer discovery mode to the second receive peer discovery mode has occurred. 
     New device detection module  1834  determines if a peer discovery signal has been received from a device from which a peer discovery signal was not previously received within a predetermined period of time. First transition condition detection module  1830  can, and sometimes does, make a change condition determination as a function of a new device detection module  1834  determination. 
     First newly discovered device counting module  1836  determines a number of newly discovered devices, said number of newly discovered devices being a number of device from which peer discovery signals are received during a second predetermined time interval but excluding devices from which peer discovery signals were received in a first predetermined period of time prior to said determination if a change condition has occurred. First transition condition detection module  1830  can, and sometimes does, make a change condition determination as a function of the number of newly discovered devices as reported by module  1836 . 1 st  predetermined time interval information  1880  and 2 nd  predetermined time interval information  1882  are used by first newly discovered device counting module  1836  in determining a number of newly discovered devices. 
     Assembly determination module  1838  determines when the number of different devices from which peer discovery signals are received in a time interval exceeds a threshold number. First transition condition detection module  1830  can, and sometimes does, make a change condition determination as a function of an assembly determination module  1838  determination. 
     Affiliation determination module  1840  determines if a peer discovery signal includes information indicating that a peer device from which the peer discovery signal was received belongs to a group of devices of interest to the communications device  1800 . First transition condition detection module  1830  can, and sometimes does, make a change condition determination as a function of the affiliation determination module  1840  determination. 
     Probabilistic determination module  1842  makes a probabilistic determination as to whether a peer discovery signal includes information indicating that the peer device from which the peer discovery signal was received belongs to a group of devices of interest to the communications device. For example, one received peer discovery signal may include a portion of a set of peer discovery information, and the probabilistic determination module  1842  can make a probabilistic determination based on the received portion of the set of discovery information, even though the complete set is unavailable at the current time to the communications device  1800 . In some embodiments, the probabilistic determination is a determination based on a portion of an ID. 
     Buddy detection sub-module  1844  uses buddy list  1872 , e.g., stored information identifying devices and/or users of devices designated as buddies of the communications device  1800 , to determine if a received peer discovery signal is from a device corresponding to an entry in the stored buddy list. 
     Service detection sub-module  1846  uses service availability list, e.g. stored information identifying services available to the communication device  1800 , to determine if a received peer discovery signal is from a device corresponding to an entry in said stored discovery availability list  1876 . 
     Application detection sub-module  1848  uses application list  1874 , e.g., stored information identifying applications of interest to the communications device  1800 , to determine if a received peer discovery signal is from a device corresponding to an entry in the stored application list  1874 . 
     Active application set tracking module  1849  determines if a change in a maintained set of application has occurred. First transition condition detection module  1830  can, and sometimes does, make a change condition determination as a function of the active application set tracking module  1849  determination. 
     Active application change module  1850  determines if a change to an active application has occurred. Exemplary changes to active applications include a mode change of an application, a configuration change of an application, and a parameter setting change of an application. First transition condition detection module  1830  can, and sometimes does, make a change condition determination as a function of the active application change module  1850  determination. 
     User input module  1851  receives input from a user of the communications device  1800  via a user I/O device included in user I/O devices  1808 , e.g., a user selection, request or command to change to the second receive peer discovery mode. First transition condition detection module  1830  can, and sometimes does, make a change condition determination as a function received user input from the user input module  1851 . 
     Second transition condition detection module  1852  determines if a change condition used to trigger a change from the second receive peer discovery mode to the first receive peer discovery mode occurred when the communications device is operating the second receive peer discovery mode. Second transition condition detection module  1852  at times makes the determination if a change condition used to trigger a change from the second receive peer discovery mode to the first receive peer discovery mode occurred as a function of a received peer discovery signal. Second mode transition control module  1854  controls the communications device to transition from the second receive peer discovery mode to the first receive peer discovery mode when the second condition detection module  1852  detects that a change condition used to trigger a change from the second receive peer discovery mode to the first receive peer discovery mode has occurred. 
     Timer module  1856  tracks the amount of time since the most recent time a condition used to trigger a transition from the first rate to the second rate was detected. Timer expiration module  1858  determines if the amount of time indicated by the timer module  1856  exceeds an expiration time. The second transition condition detection module  1852  can, and sometimes does, determine if a change condition used to trigger a change from the second receive peer discovery mode to the first receive peer discovery mode has occurred as a function of the timer expiration module  1858  determination. 
     Second newly discovered device counting module  1860  determines a number of newly discovered devices, said number of newly discovered devices being a number of devices from which peer discovery signals are received during a fourth predetermined time interval but excluding device from which peer discovery signals were received in a third predetermined period of time prior to said determination if a change condition has occurred. Third predetermined time interval information  1884  and fourth predetermined time interval information  1886  are used by module  1860  in obtaining a count. The second transition condition detection module  1852  can, and sometimes does, determine if a change condition used to trigger a change from the second mode to the first mode has occurred as a function of the number of newly discovered devices as annunciated by second newly discovered devices counting module  1860 . 
     Assembly dispersion determination module  1862  determines when the number of different devices from which peer discovery signals are received in a time interval is below a threshold number. The second transition condition detection module  1852  can, and sometimes does, determine if a change condition used to trigger a change from the second receive peer discovery mode to the first receive peer discovery mode has occurred as a function of the assembly dispersion determination module  1862  determination. 
     False identification determination module  1864  determines if a peer device which had been determined to probabilistically belong to a group of device of interest is not a member of the group of devices of interest. The second transition condition detection module  1852  can, and sometimes does, determine if a change condition used to trigger a change from the second receive peer discovery mode to the first receive peer discovery mode has occurred as a function of the false identification determination module  1864  determination. 
     Battery monitoring module  1866  monitors the amount of reserve battery power remaining in the battery  1812  and determines the current battery status condition. The second transition condition detection module  1852  can, and sometimes does, determine if a change condition used to trigger a change from the second receive peer discovery mode to the first receive peer discovery mode has occurred as a function of the battery monitoring module  1866  status determination. For example, in response to a low battery status indication the communications device is transitioned to the first receive mode so that power may be conserved and the device may operate for a longer time before a recharge is needed. 
       FIG. 19  is a drawing  1900  illustrating exemplary operations in a communications device supporting a high rate peer discovery transmit (TX) mode and a low rate peer discovery transmit (TX) mode in accordance with an exemplary embodiment. Drawing  1900  may correspond to flowchart  1500  of  FIG. 15  and/or communications device  1600  of  FIG. 16 . 
     Operation of the communications device starts in start step  1902 , where the communications device is powered on an initialized. In this embodiment, following power on, the communications device is set into the high rate transmit peer discovery state  1904 , as indicated by arrow  1906 . While in the high rate transmit peer discovery state  1904 , the communications device transmits discovery information signals conveying discovery information portions at a high rate. While in the high rate TX peer discovery state  1904 , the communications device also, on an ongoing basis, performs monitoring to detect a transition trigger for a high to low transition as indicated by arrow  1908  and operation  1910 . Some exemplary transition triggers are described with respect to block  1528  of flowchart  1500  of  FIG. 15 . If the monitoring of operation  1910  does not detect a trigger, then the communications device continues in high rate TX peer discovery state  1904  as indicated by arrow  1912 . However, if the monitoring of operation  1910  does detect a trigger, then the communications device transitions to the low rate TX peer discovery state  1906  as indicated by arrow  1914 . 
     While in the low rate transmit peer discovery state  1906 , the communications device transmits discovery information signals conveying discovery information portions at a low rate. While in the low rate TX peer discovery state  1906 , the communications device also, on an ongoing basis, performs monitoring to detect a transition trigger for a low to high transition as indicated by arrow  1916  and operation  1918 . Some exemplary transition triggers are described with respect to block  1506  of flowchart  1500  of  FIG. 15 . If the monitoring of operation  1918  does not detect a trigger, then the communications device continues in low rate TX peer discovery state  1906  as indicated by arrow  1920 . However, if the monitoring of operation  1918  does detect a trigger, then the communications device transitions to the high rate TX peer discovery state  1904  as indicated by arrow  1922 . 
       FIG. 20  is a drawing  2000  illustrating exemplary operations in a communications device supporting a high rate peer discovery receive (RX) mode and a low rate peer discovery receive (RX) mode in accordance with an exemplary embodiment. Drawing  2000  may correspond to flowchart  1700  of  FIG. 17  and/or communications device  1800  of  FIG. 18 . 
     Operation of the communications device starts in start step  2002 , where the communications device is powered on an initialized. In this embodiment, following power on, the communications device is set into the high rate receive peer discovery state  2004 , as indicated by arrow  2006 . While in the high rate receive peer discovery state  2004 , the communications device monitors discovery information signals conveying discovery information portions at a high rate. While in the high rate RX peer discovery state  2004 , the communications device also, on an ongoing basis, performs monitoring to detect a transition trigger for a high to low transition as indicated by arrow  2008  and operation  2010 . Some exemplary transition triggers are described with respect to block  1728  of flowchart  1700  of  FIG. 17 . If the monitoring of operation  2010  does not detect a trigger, then the communications device continues in high rate RX peer discovery state  2004  as indicated by arrow  2012 . However, if the monitoring of operation  2010  does detect a trigger, then the communications device transitions to the low rate RX peer discovery state  2006  as indicated by arrow  2014 . 
     While in the low rate receive peer discovery state  2006 , the communications device monitors discovery information signals conveying discovery information portions at a low rate. While in the low rate RX peer discovery state  2006 , the communications device also, on an ongoing basis, performs monitoring to detect a transition trigger for a low to high transition as indicated by arrow  2016  and operation  2018 . Some exemplary transition triggers are described with respect to block  1706  of flowchart  1700  of  FIG. 17 . If the monitoring of operation  2018  does not detect a trigger, then the communications device continues in low rate RX peer discovery state  2006  as indicated by arrow  2020 . However, if the monitoring of operation  2018  does detect a trigger, then the communications device transitions to the high rate RX peer discovery state  2004  as indicated by arrow  2022 . 
     In various embodiments, an exemplary communications device supports high and low rate TX peer discovery modes of operation and high and low rate RX peer discovery modes of operation. Thus a communications device may, and sometimes does, perform the methods of both flowchart  1500  of  FIG. 15  and flowchart  1700  of  FIG. 17  and/or include elements, e.g., a processor, modules and/or memory, etc., described with respect to communications device  1600  of  FIG. 16  and communications device  1800  of  FIG. 18 . In some embodiments, the TX peer discovery modes and the RX peer discovery modes are independent, e.g., with different trigger criteria being implemented to determine transitions for TX modes and RX modes. In some such embodiments a communications device may be, at times, in a high rate transmit peer discovery mode while being in a low rate receive peer discovery mode, or the communications device may alternatively be in a low rate transmit peer discovery mode of operation while being in a high rate receive peer discovery mode of operation. 
     In some embodiments, TX peer discovery mode transitions are coupled with corresponding RX peer discovery mode transitions, e.g., with a communications device having a peer discovery mode which is applicable to both transmit operations and receive operations. 
       FIG. 21  is a drawing  2100  illustrating exemplary nodes in a peer to peer communications system and the transmission of discovery information. The exemplary nodes are, e.g., any of the peer to peer communications devices ( 102 ,  104 ,  106 ,  108 ,  110 ) of  FIG. 1 . The exemplary nodes include a first wireless terminal  2102 , 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  2112  being transmitted along time axis  2110 . The exemplary nodes also include a second wireless terminal  2104 , 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  2114  being transmitted along time axis  2110 . The exemplary nodes also include a third wireless terminal  2106 , e.g., a third peer to peer mobile node, which is operating during a first time in a low rate discovery mode and is transmitting discovery information at a low rate, but then changes to operate in a high rate discovery mode and transmits discovery information at a high rate, as indicated by discovery signals  2116  being transmitted along time axis  2110 . In some embodiments, at least some of the wireless terminals perform discovery information transmissions in one mode but not the other. In some embodiments, at least some of the wireless terminals are multi-mode with regard to the transmission of discovery information, e.g., transmitting at low rate at some times while transmitting at a high rate at other times. 
     In some embodiments, it is possible to independently control the rate of sending and/or the rate of monitoring particular portions of peer discovery information. For example, from the senders perspective, over a given period of time multiple peer discovery related advertisements may be sent in parallel, where some are sent at a low rate and others are sent at a high rate. Similarly, from the receivers perspective, when multiple advertisements are being monitored for, some may be monitored at a low rate and others may be monitored at a high rate. 
     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, determining if a change condition occurred to trigger a change from a first peer discovery transmit mode to a second peer discovery transmit mode, transitioning from the first peer discovery transmit mode to the second peer discovery transmit mode, determining if a change condition occurred to trigger a change from the second peer discovery transmit mode to the first peer discovery transmit mode, transitioning from the second peer discovery transmit mode to the first peer discovery transmit mode, determining if a change condition occurred to trigger a change from a first peer discovery receive mode to a second peer discovery receive mode, transitioning from the first peer discovery receive mode to the second peer discovery receive mode, determining if a change condition occurred to trigger a change from the second peer discovery receive mode to the first peer discovery receive mode, transitioning from the second peer discovery receive mode to the first peer discovery receive mode, etc. 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.