Abstract:
Methods and apparatus related to a peer to peer wireless communications system supporting the association of multiple connection identifiers with a single connection between a pair of wireless terminals are described. A differentiated quality of service is supported by assigning different numbers of connection identifiers to different connections. The number of connection identifiers assigned to a wireless terminal pair for a connection is a function of one of: data rate, priority information, and quality of service information. Being allocated a higher number of connection identifiers results in being allocated a higher number of traffic transmission request resources, thus increasing the likelihood that the connection is permitted to use a traffic transmission segment. The allocation of connection identifiers is performed in a distributed manner in which handshake signaling occurs between a wireless terminal pair seeking to establish a connection, e.g., as part of a multi-step paging scheme.

Description:
FIELD 
       [0001]    Various embodiments relate to wireless communications, and more particularly, to methods and apparatus for providing different levels of peer to peer communications resources through the use of connection identifiers. 
       BACKGROUND 
       [0002]    Different connections in a wireless network may have different needs in terms of: type of traffic to be communicated, amount of traffic to communicate, priority of the traffic to be communicated, latency requirements, and/or error rate tolerances. In addition, different wireless terminals or users may have purchased different provisioning service level plans from a service provider. Traffic loading conditions can also be expected to vary over time and from one location to another. There is typically a fixed amount of air link resources in a local region available to be scheduled for traffic signaling. 
         [0003]    In a peer to peer communications network such as an ad-hoc network, where a centralized control node is not available to monitor activity, establish connections, and perform overall coordination, there is a need for new and innovative methods and apparatus to support the identification of regional activity and establish connections. 
         [0004]    In a peer to peer communications network, where boundaries are not clearly defined, one would like to be able to reuse as much of the traffic air link resources as possible in adjacent regions without creating intolerable interference levels. In systems such as ad-hoc peer to peer networks, where there is no centralized scheduling node, it becomes problematic to allocate air link resources, e.g., traffic channel air link resources in an efficient manner. 
         [0005]    Compounding the problem of the assignment of a traffic segment in a local region to a particular connection, among which various connections concurrently desire to use the same segment, is the problem that different connections may be associated with different resource needs. Allocating the same fixed amount of resources to each connection, whether it be control resources, e.g., traffic transmission request resources, or traffic transmissions resources, e.g., traffic segments, is inefficient and wasteful. 
         [0006]    Based on the above discussion, there is also a need for new and improved methods and apparatus for supporting differentiated qualities of service in a wireless communications system, e.g., in an ad-hoc peer to peer wireless communications system in which scheduling decisions are made in a distributed manner. 
       SUMMARY 
       [0007]    Methods and apparatus related to a wireless communications system supporting the association of multiple connection identifiers with a single connection between a pair of wireless terminals are described. Such methods and apparatus are well suited for peer to peer wireless communications systems, e.g., ad hoc peer to peer wireless communications systems, wherein the assignment of connection identifiers and/or the scheduling of air link resources are performed in a distributed manner. 
         [0008]    A differentiated quality of service is supported by assigning different numbers of connection identifiers to different connections. In some embodiments, the connection identifiers are orthogonal MAC IDs. For example, a first connection being established between a first pair of peer to peer wireless terminals is assigned a single connection identifier, while a second connection being established between a second pair of peer to peer wireless terminals is assigned multiple connection identifiers. In some embodiments, the first connection corresponds to users which anticipate a low traffic data rate over the first connection, while the second connection corresponds to users which anticipate a high traffic data rate over the second connection. In some embodiments, the first connection corresponds to users which anticipate higher priority traffic over the first connection, while the second connection corresponds to users which anticipate lower priority traffic over the second connection. In various embodiments, the number of connection identifiers assigned to a pair of wireless terminals for a connection is a function of a quality of service level associated with the connection. 
         [0009]    In one scheme a traffic transmission request air link resource is partitioned into a fixed number of units, e.g., OFDM tone-symbols, and each unit is associated with a different connection identifier. The units of the traffic transmission request resource are prioritized. Requests carried by the units of the traffic transmission request resource correspond to the same peer to peer traffic data segment. In some such embodiments, the transmission request unit associated with a particular connection identifier varies from one traffic slot to another, thereby providing diversity. The decision as to whether a connection, which would like to use a traffic segment, is permitted to proceed is made in a distributed manner with both potential transmitter and potential receiver having input as to whether or not to yield the traffic transmission resource to another connection or to proceed. In such an embodiment, over time, a second connection, which has been allocated more connection identifiers than a first connection, is statistically more likely to be able to use the traffic transmission resource, with other conditions remaining constant. 
         [0010]    In some embodiments, the allocation of connection identifiers is performed in a distributed manner in which handshake signaling occurs between a wireless terminal pair seeking to establish a connection. For example, a first device of the pair forms a first list of potential connection identifiers based on its understanding of currently available unused connection identifiers, and the first device communicates at least a portion of the first list to the second device of the pair as a suggested list of connection identifiers. The second device of the pair has also formed a list of currently available unused connection identifiers based on its measurements and selects one or more elements from its list that are also on received suggested list of connection identifiers. The number of selected connection identifiers to be used for the connection is, in some embodiments, determined as a function of at least one of: quality of service information communicated to the second device, an anticipated traffic data rate for the connection, a priority level associated with the connection, and a priority level associated with one of the first and second devices. The selected one or more connection identifiers to be used for the connection is communicated from the second device to the first device. In one embodiment, the handshake signaling used to reach agreement of the connection identifier or identifiers to be associated with a connection is communicated during a paging interval, e.g., using a paging channel as part of a multi-step paging process. 
         [0011]    An exemplary method operating a first communications device to communicate with a second device, in a system supporting multiple communications connections comprises: monitoring a connection identifier broadcast interval to identity unused connection identifiers; transmitting a set of available connection identifiers from the identified unused connection identifiers to the second device; receiving from the second device a subset of said transmitted set of available connection identifiers, said subset of connection identifiers including identifiers to be used for a communications connection between said first and second devices. 
         [0012]    An exemplary first communications device comprises: a connection availability signal generation module for generating a signal conveying information identifying a set of available connection identifiers; a wireless transmitter module for transmitting said generated signal conveying information identifying a set of available connection identifiers to a second device; and a wireless receiver module for receiving from the second device information indicating a subset of said transmitted set of available connection identifiers, said subset of connection identifiers including identifiers to be used for a communications connection between said first and second devices. 
         [0013]    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 
         [0014]      FIG. 1  is a drawing of an exemplary wireless communications system, e.g., an ad hoc peer to peer wireless communications system, in accordance with an exemplary embodiment. 
           [0015]      FIG. 2  is a drawing illustrating an exemplary recurring timing structure, associated exemplary air link resources, and channel information. 
           [0016]      FIG. 3  is a flowchart of an exemplary method of operating a first device to communicate with a second device in accordance with one exemplary embodiment. 
           [0017]      FIG. 4  is a drawing illustrating exemplary connection identifier mapping to air link resources, and the mapping changes between successive traffic slots in accordance with a hopping scheme. 
           [0018]      FIG. 5  is a drawing of an exemplary method of operating a first communications device to communicate with a second communications device in accordance with an exemplary embodiment. 
           [0019]      FIG. 6  comprising the combination of  FIG. 6A  and  FIG. 6B  is a flowchart of an exemplary method of operating a first wireless communications device to communicate with a second wireless communications device. 
           [0020]      FIG. 7  is a drawing of an exemplary first communications device, e.g., a mobile node supporting peer to peer communications in accordance with an exemplary embodiment. 
           [0021]      FIG. 8  is drawing illustrating various aspects of connection identifier assignment in accordance with one exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]      FIG. 1  is a drawing of an exemplary wireless communications system  100 , e.g., an ad hoc peer to peer wireless communications system, in accordance with an exemplary embodiment. Exemplary communications system  100  includes a plurality of wireless terminals (peer to peer wireless terminal A 1   102 , peer to peer wireless terminal A 2   104 , peer to peer wireless terminal B 1   108 , peer to peer wireless terminal B 2   106 , peer to peer wireless terminal N- 1   105 , . . . , peer to peer wireless terminal N  1109 ). A wireless terminal may, and sometimes does, establish a connection with another wireless terminal. One or more connection identifiers are associated with a connection between a pair of wireless terminals. As illustrated in  FIG. 1 , WT A 1   102  has a connection  110  with WT B 1   108  and the connection  110  is associated with three connection identifiers (C 1 , C 2 , C 3 ). WT A 2   104  has a connection  112  with WT B 2   106 , and the connection  112  is associated with a single connection identifier (C 4 ). At a different time different connections are established and maintained between different pairs of wireless terminals. The number of connection identifiers associated with a specific pair of wireless terminal having a connection, in some embodiments, varies over time. 
         [0023]      FIG. 2  is a drawing illustrating an exemplary recurring timing structure, exemplary air link resources and channel information. The structure of  FIG. 2  may be applicable to the system of  FIG. 1 . Exemplary timing structure  200  of  FIG. 2  includes a discovery interval  204 , a paging interval  206 , and a traffic interval  208 . During discovery interval  204  a peer to peer wireless terminal transmits a signal to make known its presence in the region, e.g., the peer to peer wireless terminal transmits a beacon signal used for identification, and the peer to peer wireless terminal monitors for identification signals from other peer to peer devices in its vicinity, e.g., other peer to peer beacon signals. In the discovery interval, a wireless terminal forms a list of discovered other wireless terminals in its vicinity. 
         [0024]    In paging interval  206  a wireless terminal may, and sometimes does, establish a connection with another wireless terminal with which it would like to communicate traffic signals. In this exemplary embodiment during the paging interval  206 , information is communicated using paging channel  250 . The paging channel  250  includes a quick paging sub-channel portion  254 , a connection ID (CID) broadcast sub-channel portion  256 , a full paging sub-channel portion  258  and a paging acknowledgement sub-channel portion  260 . 
         [0025]    Consider that exemplary WT A has discovered the presence of exemplary WT B during the discovery interval and that WT A seeks to communicate traffic to WT B. WT A sends a paging request signal to WT B using quick paging sub-channel  254  during an interval associated with quick paging. In some embodiments, the quick paging signal is a single tone signal, e.g., a single tone signal based on a discovery ID associated with WT B. 
         [0026]    Then, in an interval associated with the CID broadcast sub-channel  256 , both WT A and WT B monitor for connection ID signals from other wireless terminals which have current active connections. For example, during the CID broadcast interval, every active connection being used broadcasts a connection identifier. WT A and WT B which have been monitoring for the broadcast CIDs, each prepare a list of CIDs which are in use and then form a list of unused CIDs which are available. Since WT A and WT B are at different locations, and may be subjected to interference from different connections, the list of unused connection identifiers formed by WT A may, and sometimes does, differ from the list of unused connection identifiers that WT B forms. In some embodiments, connection identifiers are MAC identifiers. 
         [0027]    WT A identifies a set of potential connection identifiers that it thinks may be suitable for use with WT B. The set of potential connection identifiers includes identifiers which it determined to be unused based on received signals from the CID broadcast. Then, WT A transmits a signal using the full paging sub-channel  258  during an interval associated with full paging, the transmitted signal communicating the generated set of potential connection identifiers. In some embodiments, the full paging signal also communicates information used in determining a number of connection identifiers which are to be associated with the connection. In some such embodiments, the information used in determining a number of connection identifiers is quality of service information. WT B receives the full paging signal from WT A, and forms a set of connection identifier which are to be associated with the connection, members of the set of connection identifiers to be associated with the connection being included in the set of potential connection identifiers communicated via the full paging signal and being also included in WT B&#39;s list of unused connection identifiers. Then, WT B generates a paging acknowledgment signal, conveying its list of one or more connection identifiers to be associated with the connection, and transmits the generated signal to WT A using the paging acknowledgment sub-channel  260  during a paging acknowledgment sub-channel interval. 
         [0028]    Traffic interval  208  includes a plurality of traffic slots (traffic slot  1   210 , traffic slot  2   212 , . . . , traffic slot N  214 ). Traffic slot  1   210  includes a traffic transmission request resource  216 , a traffic transmission request response resource  218 , a traffic data segment resource  220  and a data acknowledgment resource  222 . Active connection identifiers include, e.g., connection identifiers for which a CID signal was broadcast using the CID broadcast sub-channel  256  and connection identifiers which were added via paging acknowledgement sub-channel signaling  260 . The active connection identifiers are utilized during the traffic interval. 
         [0029]    Each of the connection identifiers is associated with a portion of traffic transmission request resource  216 , e.g., an OFDM tone-symbol to be used for signaling a request to transmit data using traffic data segment resource. Each of the connection identifiers is associated with a portion of traffic transmission request response resource  218 , e.g., an OFDM tone-symbol to be used for signaling an RX echo signal, which is a positive response to a traffic transmission request. Traffic data segment resource  220  is used to carry peer to peer user data traffic signals for a connection, if the transmission request is granted and provided the transmitting device decided not to yield the resource. Data acknowledgement resource  222  is used to carry a traffic data acknowledgment signal in response to traffic data communicated using traffic data segment resource  220 . 
         [0030]      FIG. 3  is a flowchart of an exemplary method of operating a first device to communicate with a second device in accordance with one exemplary embodiment. The first device, wireless terminal A, is, e.g., a first peer to peer communications device and the second device, wireless terminal B, is, e.g., a second peer to peer communications device, where WT A and WT B are part of an ad hoc network. 
         [0031]    Operation starts in step  302  where the first and second devices are powered on and initialized. The first and second devices (WT A and WT B) synchronize in accordance with a recurring peer to peer timing structure, e.g., the recurring timing structure of  FIG. 2 . The first and second devices (WT A and WT B) participate in discovery, and the first device (WT A) recognizes that the second device (WT B) is in its vicinity, while the second device (WT B) recognizes that the first device (WT A) is in its vicinity. Consider that the first device (WT A) desires to page the second device (WT B) and establish an active connection. Operation proceeds from step  302  to step  304 . 
         [0032]    In step  304 , the first device (WT A) signals the second device (WT B) by putting energy on a tone corresponding to WT B during quick paging. Consider that WT B recovers the signals and recognizes that it is being paged. Operation proceeds from step  304  to step  306 . 
         [0033]    In step  306 , WT A and WT B listen during a connection identification (CID) broadcast for connection ID signals indicating CIDs which are currently in use. WT A and WT B each make a list of detected active CIDs. Operation proceeds from step  306  to step  308 . In step  308  WT A and WT B each create a list of unused connection IDs. WT A and WT B are aware of the set of designated CIDs. WT A forms its list of unused CIDs by removing its detected CIDs (of step  306 ) from the set of designated CIDs. Similarly, WT B forms its list of unused CIDs by removing its detected CIDs (of step  306 ) from the set of designated CIDs. It should be noted that WT A and WT B may, and sometimes does arrive at different sets of unused CIDs, since WT A and WT B may be situated at different locations and detect different CID signals. Operation proceeds from step  308  to step  310 . 
         [0034]    In step  310  WT A selects a set of suggested CIDs of which one or more may be used for a connection between WT A and WT B, the selection being from WT A&#39;s list of unused CIDs. For example, in step  308  WT A may have formed a list identifying eight unused CIDs, and in step  310 , WT A forms a list identifying at most 4 suggested CIDs from the 8 unused CIDs. In step  310  the WT A generates a full paging interval signal to convey its list of suggested CIDs for the connection between WT A and WT B. In some embodiments, QoS information is included with the list of suggested CIDs in the generated signal. Operation proceeds from step  310  to step  312 . 
         [0035]    In step  312 , WT A transmits during a full paging interval the generated list of suggested CIDs, and optionally includes quality of service information which may indicate a desired use of multiple CIDs. Operation proceeds from step  312  to step  314 . 
         [0036]    In step  314 , WT B receives the paging information transmitted by WT A in step  312 . Then, in step  316 , WT B selects one or more CIDs depending on the QoS required from the suggested list of CIDs which has been communicated. The selected CIDs are CIDs which are included in both the suggested list of CIDs from WT A and the list of unused CIDs which WT B formed based on received broadcast CIDs detected by WT B during the CID broadcast interval. Operation proceeds from step  316  to step  318 . 
         [0037]    In step  318 , WT B signals to WT A during a paging acknowledgment interval the one or more selected CIDs from step  316 . WT B receives the paging acknowledgment signal and identifies the one or more selected CIDs to be used for the connection between WT A and WT B. Operation proceeds from step  318  to step  320 . 
         [0038]    In step  320 , WT A and WT B determine mapping for a current traffic slot between CIDs and tones used for traffic transmission requests and traffic transmission request responses, e.g., RX echos. The mapping between a connection identifier and request/request response resource may, and sometimes does, change from one traffic slot to the next, e.g., in accordance with an implemented hopping pattern known to both WT A and WT B. This hopping provides diversity, e.g., increasing the likelihood that a transmission traffic request corresponding to a connection identifier will have an opportunity to transmit traffic during at least one of the traffic slots in the traffic interval. Priorities are associated with positions within the traffic transmission request resource; therefore, moving a connection identifier to a different traffic transmission request resource tone-symbol from one traffic slot to another, in accordance with hopping, changes request priorities. Operation proceeds from step  320  to step  322 . 
         [0039]    In step  322  a first one of WT A and WT B transmits a traffic transmission request to a second one of WT A and WT B using the highest priority request resource corresponding to the one or more selected CIDs, said resource used for transmission being a tone in a set of time frequency resources for the duration of an OFDM symbol transmission time interval. Operation proceeds from step  322  to step  324 . 
         [0040]    In step  324 , the second one of WT A and WT B transmits an RX echo signal using an air link resource in a traffic transmission request response interval which corresponds to the request resource. The decision to transmit an RX echo signal represents a decision to accept the received traffic transmission request directed to the second one of WT A and WT B, which was transmitted in step  322 . If the second one of WT A and WT B had instead decided not to accept the request, the second one of WTA and WT B would refrain from signaling an RX echo signal. Operation proceeds from step  324  to step  326 . 
         [0041]    In step  326 , the first one of WT A and WT B, which has received the transmitted RX echo of step  324 , transmits data to the second one of WT A and WT B in the traffic slot, e.g., using traffic data segment resource  220 . Operation proceeds from step  326  to step  328   
         [0042]    In step  328 , the second one of WT A and WT B, sends an Acknowledgment in response to the received traffic data, e.g., using data ack resource  222 . 
         [0043]    Note that flowchart  300  has been presented for the case where the decision is to proceed with the establishment of a connection, selection and agreement on one or more connection identifiers to use for the connection is possible and occurs, and traffic transmission request/response signals results in the communications of traffic signals between the first and second wireless devices. Operation may deviate from the positive results flowchart of  FIG. 3  based on any of a number of conditions, e.g., no connection identifiers are currently available, there is no overlap between WT A&#39;s list of unused connection identifiers and WT B&#39;s list of unused connection identifiers, the WT which would like to request a traffic transmission resource decides to refrain from sending a request, e.g., due to a higher priority request which it detected. The WT which is intended to receive the traffic transmission signals decides to perform receiver yielding and not send an RX echo, etc. 
         [0044]    Steps  322  to  328 , in some embodiments, are performed multiple times, e.g., corresponding to a plurality of traffic slots during which at least one one of WT A and WT B desires to transmit traffic signals. For example, the same one or more CIDs signaled from WT B to WT A in step  318  are to be used for the connection between WT A and WT B during a plurality of traffic slots, e.g., (traffic slot  1   210 , traffic slot  2   212 , traffic slot N  214 ). 
         [0045]      FIG. 4  is a drawing  400  illustrating exemplary connection identifier mapping to air link resources, and the mapping changes between successive traffic slots in accordance with a hopping scheme. In  FIG. 4 , one may assume that a connection, e.g., between peer to peer WT A and peer to peer WT B has been established, e.g., during a paging interval, and that three connection identifiers (C 1 , C 2 , C 3 ) are now associated with the connection. 
         [0046]    Drawing  402  illustrates an exemplary traffic slot  1  transmission request resource which includes  16  OFDM tone-symbols, each tone-symbol associated with a connection identifier in accordance with a predetermined mapping. Vertical axis  410  represents tone index, which in this example, ranges from 0 to 3. Horizontal axis  412  represents OFDM symbol index in the transmission request resource block  412 , which ranges from 0 to 3. Note that low ranges of tone indexes and symbol indexes are being used for the purposes of illustration; however, the actual number of tones used and/or symbols used may be other than 4. For example, in one exemplary embodiment there are 256 distinct units, e.g., OFDM tone-symbols available in a transmission request resource block to carry requests, e.g., corresponding to 256 different MAC IDs. 
         [0047]    In this example, each OFDM tone-symbol of the TX request resource is associated with a different priority level. OFDM tone-symbols corresponding to lower OFDM symbol indexes have higher priority than OFDM tone-symbols corresponding to higher OFDM symbol indexes. For a give OFDM symbol index, an OFDM tone-symbol corresponding to a higher index tone has higher priority than an OFDM tone-symbol corresponding to a lower index tone. OFDM tone-symbol  414  is the tone-symbol having the highest request priority, while OFDM tone-symbol  416  is the tone-symbol having the lowest request priority. 
         [0048]    In this example, there are three connection identifiers corresponding to the connection between WT A and WT B, where connection identifier C 1  is mapped to OFDM tone-symbol  414 , connection identifier C 2  is mapped to OFDM tone-symbol  420 , and connection identifier C 3  is mapped to OFDM tone-symbol  422 . It should be noted that of the three connection identifiers C 1  is associated with the highest priority, and therefore, if WT A decides to send a traffic transmission request to WT B for traffic slot  1 , WT A will use OFDM tone-symbol  414 , as indicated by the circle around C 1 . 
         [0049]    Drawing  404  illustrates an exemplary traffic slot  1  transmission request response resource, e.g. an RX echo resource, which includes 16 OFDM tone-symbols, each tone-symbol associated with a connection identifier in accordance with a predetermined mapping. Vertical axis  424  represents tone index, which in this example, ranges from 0 to 3. Horizontal axis  426  represents OFDM symbol index in the transmission request response resource block, which ranges from 0 to 3. 
         [0050]    In this example, there are three connection identifiers corresponding to the connection between WT A and WT B, where connection identifier C 1  is mapped to OFDM tone-symbol  428 , connection identifier C 2  is mapped to OFDM tone-symbol  430 , and connection identifier C 3  is mapped to OFDM tone-symbol  432 , which are designated to be used to transmit request response signals, e.g., an RX echo signal from WT B to WT A. For example, consider that WT A has transmitted a traffic transmission request on resource  414  (associated with connection identifier C 1 ), then WT B, if it decides to acquiesce to the request, transmits a RX echo signal on OFDM tone-symbol  428  (associated with connection identifier C 1 ). 
         [0051]    Drawing  406  illustrates an exemplary traffic slot  2  transmission request resource which includes  16  OFDM tone-symbols, each tone-symbol associated with a connection identifier in accordance with a predetermined mapping. Vertical axis  440  represents tone index, which in this example, ranges from 0 to 3. Horizontal axis  442  represents OFDM symbol index in the transmission request resource block, which ranges from 0 to 3. Note that low ranges of tone indexes and symbol indexes are being used for the purposes of illustration; however, the actual number of tones used and/or symbols used may be other than 4. In this example, each OFDM tone-symbol of the TX request resource is associated with a different priority level. OFDM tone-symbols corresponding to lower OFDM symbol indexes have higher priority than OFDM tone-symbols corresponding to higher OFDM symbol indexes. For a given OFDM symbol index, an OFDM tone-symbol corresponding to a higher index tone has higher priority than an OFDM tone-symbol corresponding to a lower index tone. OFDM tone-symbol  444  is the tone-symbol having the highest request priority, while OFDM tone-symbol  446  is the tone-symbol having the lowest request priority. 
         [0052]    In this example, there are three connection identifiers corresponding to the connection between WT A and WT B, where connection identifier C 1  is mapped to OFDM tone-symbol  450 , connection identifier C 2  is mapped to OFDM tone-symbol  448 , and connection identifier C 3  is mapped to OFDM tone-symbol  452 . It should be noted that of the three connection identifiers C 2  is associated with the highest priority, and therefore, if WT A decides to send a traffic transmission request to WT B for traffic slot  2 , WT A will use OFDM tone-symbol  448 , as indicated by the circle around C 2 . 
         [0053]    Drawing  408  illustrates an exemplary traffic slot  2  transmission request response resource, e.g. an RX echo resource, which includes 16 OFDM tone-symbols, each tone-symbol associated with a connection identifier in accordance with a predetermined mapping. Vertical axis  454  represents tone index, which in this example, ranges from 0 to 3. Horizontal axis  456  represents OFDM symbol index in the transmission request response resource block, which ranges from 0 to 3. 
         [0054]    In this example, there are three connection identifiers corresponding to the connection between WT A and WT B, where connection identifier C 1  is mapped to OFDM tone-symbol  460 , connection identifier C 2  is mapped to OFDM tone-symbol  458 , and connection identifier C 3  is mapped to OFDM tone-symbol  462 , which are designated to be used to transmit request response signals, e.g., an RX echo signal from WT B to WT A. For example, consider that WT A has transmitted a traffic transmission request on resource  448  (associated with connection identifier C 2 ), then WT B, if it decides to acquiesce to the request, transmits a RX echo signal on OFDM tone-symbol  458  (associated with connection identifier C 2 ). 
         [0055]      FIG. 5  is a drawing of an exemplary method of operating a first communications device to communicate with a second communications device in accordance with an exemplary embodiment. The first and second communications devices are, e.g., peer to peer communications devices, in an ad-hoc peer to peer communications network. Operation of the exemplary method starts in step  502 , where the first communications device is powered on and initialized and proceeds to step  504 . 
         [0056]    In step  504 , the first communications device monitors a connection identifier broadcast interval to identify unused connection identifiers. Operation proceeds from step  504  to step  506 . 
         [0057]    In step  506  the first communications device transmits a set of available connection identifiers from the identified unused connection identifiers to the second device. Then, in step  508  the first device receives from the second device a subset of the transmitted set of available connection identifiers, the subset of connection identifiers including identifiers to be used for a communications connection between the first and second devices. In some embodiments, the connection is a bi-directional connection. The received subset may, and sometimes does, include multiple connection identifiers corresponding to a single communications link between the first and second devices. In some embodiments, different traffic transmission resources are associated with different connection identifiers, the different traffic transmission resources having different priorities. In some embodiments, transmission request resources are tone-symbols in a set of time-frequency resources. Operation proceeds form step  508  to step  510 . 
         [0058]    In step  510  the first device uses a connection identifier in the received subset to communicate with the second device. Step  510  includes sub-steps  512 ,  514  and  516 . In sub-step  512  the first device transmits a traffic transmission request to the second device using the highest priority traffic transmission request resource which corresponds to one of the received subset of multiple connection identifiers. Operation proceeds from step  512  to step  514 . In step  514  the first device receives a transmission request echo from the second device on a transmission request echo resource corresponding to the traffic transmission resource used to transmit the traffic transmission request. Then, in step  516  the first device transmits data to the second device during a traffic interval corresponding to the transmitted traffic request. Operation proceeds from step  510  to step  518 . 
         [0059]    In step  518  the first device determines a new mapping of transmission request resources to connection identifiers. Then, in step  520  the first device transmits another traffic transmission request to the second device using the highest priority traffic transmission resource which corresponds to one of the received subset of multiple connection identifiers as determined during the mapping operation. 
         [0060]      FIG. 6  comprising the combination of  FIG. 6A  and  FIG. 6B  is a flowchart  600  of an exemplary method of operating a first wireless communications device to communicate with a second wireless communications device. The first and second wireless communications devices are, e.g., peer to peer communications devices in an ad-hoc network following a recurring peer to peer timing structure in the network. Operation starts in step  602 , where the first communications device is powered on and initialized and proceeds to step  604 . In step  604 , the first communications device monitors a connection identifier broadcast interval to identify unused connection identifiers. Step  604  includes sub-step  606  in which the first device forms a list of unused connection identifiers. Operation proceeds from step  604  to step  608 . 
         [0061]    In step  608  the first communications device makes a decision as to whether it desires to communicate with a second communications device. If the first device does not wish to communicate with a second device, then, operation proceeds from step  608  via connecting node A  609  to step  604  for monitoring during the next connection identifier broadcast interval. However, if the first device wishes to communicate with the second device, then operation proceeds from step  608  to step  610 . 
         [0062]    In step  610 , the first device transmits a set of available connection identifiers, from the list of identified unused connection identifiers, to the second device. Then, in step  612 , the first communications device monitors to receive a response from the second device. Step  612  includes, at times, sub-step  614 , in which the first communications device receives from the second device a subset of the transmitted set of available connection identifiers, said subset of connection identifiers including identifiers to be used for a communications connection between the first and second devices. In some embodiments, the connection is a bidirectional connection. In some embodiments, the received subset may, and sometimes does, include multiple connection identifiers corresponding to a single communications link between the first and second devices. In various embodiments, different traffic transmission resources are associated with different connection identifiers, and the different traffic transmission resources have different priorities. Operation proceeds from step  612  to step  616 . 
         [0063]    In step  616  the first communications device determines if a response was received from the second device. If a response was not received, then operation proceeds from step  616  via connecting node A  609  to step  604  where the first communications device monitors during the next connection identifier broadcast interval. However, in step  616  if the first communications device determines that a response was received from the second device, then operation proceeds from step  616  to step  618 . 
         [0064]    In step  618 , the first device selects a connection identifier included in the received subset to communicate with the second device. The selected connection identifier is subsequently used to communicate with the second device, e.g., in steps  624 ,  626  and/or  632 . In some embodiments, the connection identifier which is selected, is selected as a function of priority information and corresponds to the highest priority traffic transmission resource of the received subset of multiple connection identifiers. Operation proceeds from step  618  via connecting node B  619  to step  620 . In step  620 , the first communications device identifies a set of traffic transmission resources corresponding to the selected connection identifier, e.g., a transmission request resource, a transmission request response resource and a traffic segment resource. In some embodiments, different traffic transmission resources are associated with different connection identifiers, the different traffic transmission resources having different priorities. In some embodiments, transmission request resources are tone-symbols in a set of time-frequency resources. In some embodiments, step  620  includes sub-step  622 . In sub-step  622  the first communications device uses current time index information in a recurring timing structure in determining connection identifier to transmission request resource mapping information. Thus mapping of transmission request resources to connection identifiers, in some embodiments, change over time, e.g., to provide diversity. 
         [0065]    Operation proceeds from step  620  to step  624 . In step  624  the first device transmits a traffic transmission request to the second device using the traffic transmission request resource corresponding to the selected connection identifier. Then, in step  626  the first communications device monitors to receive a response to the transmitted traffic transmission request from the second device. Step  626  may, and sometimes does, include sub-step  628 . In sub-step  628  the first communications device receives a transmission request echo from the second device on a transmission request response resource corresponding to the traffic transmission request resource used to transmit the traffic transmission request. Operation proceeds from step  626  to step  630 . 
         [0066]    In step  630  the first communications device determines if an RX echo signal was received from the second communications device, e.g., communicating a positive response to the traffic transmission request. If an RX echo signal was not received, then operation proceeds from step  630  via connecting node A  609  to step  604  for monitoring during the next connection identifier broadcast interval. However, if an RX echo signal was received, then operation proceeds from step  630  to step  632 , in which the first communications device transmits data to second device during a traffic interval corresponding to the transmitted traffic request. Operation proceeds from step  632  via connecting node A  609  to step  604 . 
         [0067]      FIG. 7  is a drawing of an exemplary first communications device, e.g., a mobile node supporting peer to peer communications in accordance with an exemplary embodiment. Exemplary first communications device  700  includes a wireless receiver module  702 , a wireless transmitter module  704 , user I/O devices  708 , a processor  706 , and memory  710  coupled together via a bus  712  over which the various elements may interchange data and information. 
         [0068]    Memory  710  includes routines  718  and data/information  720 . The processor  706 , e.g., a CPU, executes the routines  718  and uses the data/information  720  in memory  710  to control the operation of the communications device  700  and implement methods, e.g., the method of flowchart  300  of  FIG. 3 , the method of flowchart  500  of  FIG. 5  or the method of flowchart  600  of  FIG. 6 . 
         [0069]    Wireless receiver module  702 , e.g., an OFDM receiver, is coupled to receive antenna  714  via which the communications device  700  receives signals from other peer to peer communications devices. Received signals include, e.g., connection identifier usage signals, e.g., signals  744  and  746 , connection availability response signals, e.g., signal  752 , and transmission request response signals, e.g., signal  764 . 
         [0070]    Wireless transmitter module  704 , e.g., an OFDM transmitter, is coupled to transmit antenna  716  via which the communications device  700  transmits signals to other peer to communications devices. In some embodiments, the same antenna is used for the receiver and the transmitter. Transmitted signals include connection availability signals, e.g., signal  750 , traffic transmission request signals, e.g., signal  762 , and traffic signals, e.g., signal  766 . 
         [0071]    Routines  718  include a communications routine  722  and wireless terminal control routines  724 . The communications routine  722  implements the various communications protocols used by the communications device  700 . The wireless terminal control routines  724  include a connection identifier monitoring module  726 , a connection availability signal generation module  728 , a connection availability response signal recovery module  730 , a peer communications control module  732 , a traffic transmission request signal generation module  734 , a resource selection module  736 , a request response monitoring module  738 , a traffic data control module  740  and a connection identifier to transmission resource mapping module  742 . 
         [0072]    Data/information includes a plurality of detected signals corresponding to unavailable connection identifiers (detected signal corresponding to a first unavailable connection identifier  744 , . . . , detected signal corresponding to an Nth unavailable connection identifier  746 ), a list of determined unused connection identifiers  748 , a generated available connection identifier set signal  750 , a received signal conveying available connection identifier subset information  752 , a recovered subset of available connection identifiers  754 , a determined highest priority resource  756 , a selected connection identifier  758 , information identifying resources corresponding to the selected identifier  760 , a generated traffic transmission request signal  762 , a received RX echo signal  764 , and a generated traffic signal  766 . Data/information  720  also includes information associating traffic transmission resources with connection identifiers  782  and timing/frequency structure information  768 . The timing frequency structure information  768  includes information corresponding to a plurality of intervals in a recurring timing structure (slot  1  information  770 , . . . , slot N information  772 ). Slot  1  information  770  includes connection ID broadcast interval information  774 , connection ID handshaking interval information  776 , TX request/response interval information  780  and traffic data interval information  780 . In some embodiments, the slot  1  information  770  includes information identifying and/or defining multiple TX request/response/traffic data interval sets corresponding to a single connection ID broadcast interval/connection ID handshaking interval pair. Thus established and agreed upon connection IDs are, in such an embodiment, used for multiple successive traffic slots in a traffic interval. 
         [0073]    Connection identifier monitoring module  726  detects signals received during a connection identifier broadcast interval and determines unused connection identifiers. Connection identifier monitoring module  726  determines a set of available connection identifiers including connection identifiers indicated by signals received during the connection identifier broadcast interval to be unused connection identifiers. Detected signal corresponding to first unavailable connection identifier  744  and detected signal corresponding to N unavailable connection identifier are signal detected by connection identifier monitoring module  726  while list of determined unused connection identifiers  748  is an output of connection identifier monitoring module  726 . 
         [0074]    Connection availability signal generation module  728  generates a signal conveying information identifying a set of available connection identifiers. List of determined unused connection identifiers  748  is an input to connection availability signal generation module  728  while generated available connection identifier set signal  750  is an output of module  728 . 
         [0075]    Connection availability response signal recovery module  730  identifiers a subset of available connection identifiers from a signal received from the communications device to which the generated available connection identifier set signal was communicated. Received signal conveying available connection identifier subset  752  is an input to connection availability response signal recovery module  730 , while recovered subset of available connection identifiers  754  is an output of module  730 . In various embodiments, the subset includes, at times, multiple connection identifiers corresponding to a single communications link between the first communications device and a second communications device. 
         [0076]    Peer communications control module  732  uses a connection identifier included in the received subset identified by information  754  to communicate with a second device, e.g., the device which transmitted the subset, over a connection. In various embodiments, the connection is a bi-directional connection. 
         [0077]    Resource selection module  736  selects to use the highest priority traffic transmission resource which corresponds to one of the received subset of multiple connection identifiers. For example, each of the connection identifiers of the subset is associated with a different traffic transmission request resource and the different traffic transmission request resources are associated with different priorities. The resource selection module  736  selects the highest priority traffic transmission resource corresponding to a member of the subset for transmission of the request. This selection also by virtue of the linkage between transmission traffic request resources and connection identifiers also selects a connection identifier. Determined highest priority resource  756  and selected connection identifier  758  are outputs of the resource selection module  736 . 
         [0078]    Traffic transmission request signal generation module  734  generates a traffic transmission request to another device, e.g., to a second device. Generated traffic transmission request  762  is an output of module  734 . The generated traffic transmission request is communicated using the traffic transmission request resource, e.g., OFDM tone-symbol, identified by determined highest priority resource  756  and corresponding to selected connection identifier  758 . 
         [0079]    Request response monitoring module  738  monitors a transmission request response resource to detect the reception of a transmission request response signal, e.g., an RX echo signal, from the device to which the request was transmitted. For example, corresponding to the request resource which conveyed the traffic transmission request, there is a corresponding request response resource. If the device to which the request was sent, e.g., the second device, acquiesces to the request it responds by transmitting an RX echo signal using that request response resource. However, if it des not acquiesce to the request then it does not transmit an RX echo signal. Received RX echo signal  764  is a signal detected by request response monitoring module  738 , e.g., signifying that the first wireless device  700  may proceed with the traffic signaling. 
         [0080]    Traffic data control module  740  controls the transmitter module  704  to transmit data to another device, e.g., the second device, during a traffic interval corresponding to a transmitted traffic request, e.g., a transmitted traffic request for which an RX echo signal was received. Generated traffic signal  766 , e.g., a peer to peer traffic signal communicating user data such as text data, audio data and/or image data, is transmitted by wireless transmitter module  704  under the direction of traffic data control module  740 . 
         [0081]    Connection identifier to transmission resource mapping module  742  determines a mapping of transmission resources including transmission request resources to connection identifiers as a function of time. Thus connection identifier to transmission resource mapping module  742  determines a mapping of transmission request resources to connection identifiers for a first time interval and for a second time interval, the first and second time intervals being different, and the mapping between request resources and connection identifiers changing between first and second time intervals. Connection identifier to transmission resource mapping module  742  uses stored information associating traffic transmission resources with connection identifiers  782  and timing/frequency structure information  768  in determining the mappings. 
         [0082]    Connection ID broadcast interval information  774  identifies a time interval for which the connection identifier monitoring module  726  operates. Connection ID handshaking interval information  776  identifies an interval during which a connection availability signal and a connection availability response signal are communicated. TX request/response interval information  778  identifies an interval during which a transmission traffic request signal and an RX echo signal are communicated. Traffic interval information  780  identifies an interval during which a traffic signal, e.g., a peer to peer traffic signal, is communicated. 
         [0083]      FIG. 8  is drawing illustrating various aspects of connection identifier assignment in accordance with one exemplary embodiment. In  FIG. 8  exemplary peer to peer wireless communications system  800  includes a plurality of peer to peer wireless terminals (WT  1   802 , WT  2   804 , WT  3   806 , WT  4   808 , WT  5   810 , WT  6   812 , WT  7   814 , WT  8   816 , WT  9   818 , WT  10   820 ). The WTs of  FIG. 8  are, e.g., WTs in accordance with WT  700  of  FIG. 7  and/or in accordance with the method of flowchart  300  of  FIG. 3 , flowchart  500  of  FIG. 5  and/or flowchart  600  of  FIG. 6 . Active connections exist between four pairs of the wireless terminals. Connection  824  exists between WT  2   804  and WT  5   810 , and the connection is associated with one connection identifier, C 2 . Connection  826  exists between WT  3   806  and WT  4   808 , and the connection is associated with two connection identifiers, C 4  and C 6 . Connection  822  exists between WT  7   814  and WT  8   816 , and the connection is associated with one connection identifier, C 1 . Connection  828  exists between WT  9   818  and WT  10   820 , and the connection is associated with one connection identifier, C 5 . During a connection identifier broadcast interval, wireless terminals corresponding to existing active connections broadcast their connection identifier information. 
         [0084]    In this example, WT  1   802  and WT  6   812 , which are aware of the presence of each other, desire to establish a connection, which is represented by dotted line  830 . Drawing  850  illustrates various operations performed to reach agreement on the connection identifier or identifiers to be used for the connection. Axis  851  illustrates time. During the connection identifier broadcast interval, both WT  1   802  and WT  6   812  have been monitoring, and identify detected connection identifiers. Since WT  1  and WT  6  are at different locations, they may detect different connection identifiers in use. In this embodiment, there are a set of  256  different connection identifiers which can assigned. WT  1  and WT  6  each form a list of unused connection identifiers from their perspective. Block  852  indicates the WT  1  unused connection list is: C 3 , C 5 , and C 6 -C 256 . Block  854  indicates the WT  6  unused connection list is: C 1 , C 3 , and C 6 -C 256 . In this example, WT  1  happens to initiate the connection request to WT  6 , forms a suggested connection list, generates a signal communicating the suggested list and quality of service information, and communicates the generated signal to WT  6 . The quality of service information is used to derive the number of connection identifiers to be assigned to the connection. Block  856  indicates that the WT  1  suggested connection list is: C 3 , C 5 , C 6 , C 7 , C 8  and the QoS information indicates that WT  1  would like  3  connection identifiers to be assigned. WT  6  receives the signal conveying the suggested list of connection identifiers to be used and quality of service information, and processes the received signal. WT  6  selects three connection identifiers from the suggested list which are also included in its unused connection list  854 . WT  6  generates a response signal communicating the selected list of connection identifiers to be used for the connection, and transmits the signal to WT  1 . Block  858  indicates the selected connection list includes C 3 , C 6  and C 7 . WT  1  receives the list of suggested connection identifiers. 
         [0085]    WT  1  and WT  6  use the list of selected connection identifiers for operations with their connection  830 , e.g., identifying resources which have been allocated to connection such as transmission request resources, corresponding transmission request response resources, and traffic transmission resources for peer to peer traffic transmission operations. Those identified resources are used by WT  1  and WT  6  in the communication of peer to peer traffic signals. 
         [0086]    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 terminals, base stations, communications system. 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. 
         [0087]    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, signal processing, a decision step, message generation, message signaling, switching, reception and/or transmission steps. 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. 
         [0088]    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. 
         [0089]    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. 
         [0090]    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. 
         [0091]    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.