Patent Publication Number: US-7720485-B2

Title: Methods and apparatus related to assignment in a wireless communications system

Description:
FIELD OF THE INVENTION 
   This invention relates to multi-user communications systems and, more particularly, to methods and apparatus related to assignment in a wireless communication system. 
   BACKGROUND 
   As the popularity of wireless communications systems increases and the variety of types of data communications services offered increases, there is an ever increasing demand for the limited available air link resources, e.g., frequency spectrum, allocated to a given base station for its cell. In addition, the number of users and user demand for resources can vary as a function of time and events which can cause anticipated and unanticipated peaks in demand. High numbers of concurrent active users in a cell create challenges to satisfy the users&#39; needs to communicate uplink and/or downlink user data in a timely manner while not expending a large portion of those air link resources for control signaling purposes. Resources that are utilized for control signaling purposes such as assignments reduce the amount of resources available to communicate user data. Complicating the efficient use of resources is the fact that, there are typically a variety of different types of users and/or applications which may have different traffic channel resource demands and requirements such as latency, acceptable error rate, etc. 
   One method of assignment used for traffic channel segments, is for a base station attachment point to allocate a unique base station assigned user identifier to each of the wireless terminals it is to be servicing, and then include that assignment identifier in an assignment message. However, as the number of potential current users increases, the number of bits needed to uniquely represent the user identifier increases, thus increasing the overhead signaling in each communicated assignment message. Generally this method also treats each of the users equally in that each user could potentially be assigned to any given traffic channel segment, even though some of the users may be more likely to be allocated a high number of traffic channel segments while others may be allocated a low number of traffic channel segments than other users in a given time interval. 
   While the known assignment method may be adequate for some applications, it would be beneficial if new and improved methods and apparatus were available for traffic channel assignment. It would be desirable if at least some new methods and apparatus could efficiently support a high number of users, provide flexibility in terms of accommodating different types of users/applications/current needs, and/or limit control signaling overhead as compared to other techniques. 
   SUMMARY 
   Methods and apparatus for communicating resource assignment information, e.g., traffic channel segment assignment information, and using such assignment information are described. Various exemplary methods and apparatus can be used in a system including both base stations and wireless terminals. Thus, it should be appreciated that some methods are applicable to base stations while other methods are applicable to wireless terminals. 
   An exemplary method of operating a base station, in accordance with some but not necessarily all embodiments, includes: communicating a base station assigned wireless terminal identifier and a corresponding mask value to a wireless terminal and subsequently communicating a first type of assignment message to the wireless terminal, said first type of assignment message including a wireless terminal identifier and a mask identifier value. The base station assigned wireless terminal identifier and corresponding mask value are, in some embodiments, communicated as part of a state transition message. The first type of assignment message may be a traffic channel assignment message. 
   The received mask value is, in some embodiments, used to determine the mode of operation to which the wireless terminal is being transitioned. Different On state modes of operation may correspond to different levels of available resources which may be utilized, and the received mask value may be used to identify the mode and at least some of those available resources. 
   The information from the state transition message may subsequently be used by the wireless terminal when processing assignment messages, e.g., traffic channel assignment messages, to determine whether or not the assignment is directed to the wireless terminal. 
   An exemplary base station, in accordance with some embodiments, includes a wireless terminal control message generation module for generating message information directed to a wireless terminal, said message information communicating a base station assigned wireless terminal identifier and a corresponding mask value; a first type assignment message generation module for generating an assignment message of a first type including said wireless terminal identifier and a mask identifier value; and a transmitter for transmitting said wireless terminal control message information and said first type assignment message. 
   An exemplary method of operating a wireless terminal, in accordance with some embodiments, includes: receiving a base station assigned wireless terminal identifier and a corresponding mask value from a base station; and receiving a first type of assignment message from said base station, said first type assignment message including a wireless terminal identifier and a mask identifier value. 
   An exemplary wireless terminal, in accordance with some embodiments, includes: a control message processing module for processing received control message information including a base station assigned wireless terminal identifier and a corresponding mask value, and a first type assignment message processing module for processing assignment messages of a first type, said first type assignment messages including a wireless terminal identifier and a mask identifier value. 
   Various but not necessarily all embodiments also include and use second type assignment messages in addition to first type assignment messages. In some embodiments second type assignment messages include a wireless terminal identifier but do not include a mask identifier value. In various embodiments, predetermined mapping associations between assignment slots, e.g., in an assignment channel, and traffic channel segments, e.g., in a traffic channel, are utilized to reduce control signaling. In one such embodiment the assignment and traffic channels are part of a recurring channel structure. In some embodiments, predetermined associations between traffic channel segments and mask information exists and is used to reduce control signaling. 
   In one particular exemplary embodiment a wireless communications system implements an uplink dedicated control channel (DCCH) supports both a full-tone format DCCH format and a split-tone DCCH format. In such an embodiment, if a logical DCCH channel tone is in full-tone format, each of the DCCH segments corresponding to the tone are associated with a single wireless terminal. If a logical DCCH tone is in split-tone format, the DCCH segments corresponding to the tone include a plurality of non-overlapping subsets, and each subset can be associated with a wireless terminal. 
   In the particular exemplary embodiment, a wireless terminal may receive, from a base station attachment point, a base station assigned ON-state identifier which is associated with a corresponding DCCH tone to be used by the wireless terminal. In addition, in accordance with the particular exemplary embodiment, the wireless terminal may receive an assignment mask. The bit pattern of the assignment mask identifies whether the DCCH tone to be used by the wireless terminal is in full-tone format or split-tone format. In addition, when split-tone format is indicated, the bit pattern further identifies which one or more non-overlapping subsets of DCCH segments associated with the logical tone are to be used by the wireless terminal. 
   In the particular exemplary embodiment, a recurring downlink/uplink traffic channel structure includes indexed segments, each indexed segment associated with a flash type assignment or regular type assignment. Each indexed traffic channel segment associated with a flash type assignment is associated, via a predetermined mapping, with a wireless terminal On-Mask bit pattern including one set bit. Each indexed traffic channel segment associated with a regular type assignment is associated, via a predetermined mapping, with two different wireless terminal On-Mask bit patterns, each of the two different bit patterns having a different single set bit. 
   A flash assignment for a traffic channel segment in the particular exemplary embodiment includes an ON-state identifier field, which carries the On-state identifier of the WT to which the assignment is directed. A wireless terminal in full-tone DCCH mode, by checking its assigned WT On-state identifier against the value in the On-state identifier field recognizes whether or not the assignment is directed toward itself. A wireless terminal in split tone DCCH mode compares its assigned On-state mask to the predetermined ON state mask associated with the segment to determine if the assignment can potentially be directed to itself; for segments in which the assignment can be directed to the wireless terminal, the wireless compares its assigned On state identifier to the value in the On-state identifier field of the flash assignment to determine whether or not it is the intended recipient of the assignment. 
   A regular assignment for a traffic channel segment in the particular exemplary embodiment includes a single bit On-Mask subfield in addition to an ON-state identifier subfield. The bit pattern of the On-Mask subfield identifies which of the two different potential wireless terminal On-Mask bit patterns applies to the segment assignment. A wireless terminal in full-tone format DCCH mode, by checking its assigned WT On-state identifier against the value in the On-state identifier field recognizes whether or not the assignment is directed toward itself. A wireless terminal in split-tone format DCCH mode compares its assigned On state mask to predetermined On state masks which can be associated with the segment to determine if the segment can potentially directed to itself. For a segment in which the assignment can be directed to the wireless terminal, the wireless terminal in split-tone DCCH mode, decodes the received value of the On-Mask subfield to determine an On-state mask. Then the wireless terminal can compare its assigned On-state mask to the decoded ON state mask currently associated with the segment to determine if the assignment can potentially be directed to itself. For segments in which the assignment can be directed to the wireless terminal, the wireless compares its assigned On state identifier to the value in the On-state identifier field of the assignment to determine whether or not it is the intended recipient of the assignment. 
   While the particular exemplary embodiment describes various steps being performed in a particular order, it should be appreciated that the order of various steps may vary depending on a given implementation. 
   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 communication system implemented in accordance with various embodiments. 
       FIG. 2  is a drawing of an exemplary base station, e.g., access node, implemented in accordance with various embodiments. 
       FIG. 3  is a drawing of an exemplary wireless terminal, e.g., mobile node, implemented in accordance with various embodiments. 
       FIG. 4  illustrates exemplary state transition message signaling, dedicated control channel tones, the assignment of wireless terminal ON state identifier and wireless terminal On mask, in accordance with various embodiments. 
       FIG. 5  illustrates exemplary flash assignment message signaling of a traffic channel segment and exemplary regular assignment message signaling including one or more assignments in accordance with various embodiments, each of the one or more assignments corresponding to a different traffic channel segment. 
       FIG. 6  comprising the combination of  FIG. 6A ,  FIG. 6B , and  FIG. 6C  is a flowchart of an exemplary method of operating a wireless terminal in accordance with various embodiments. 
       FIG. 7  is a table of an exemplary specification of downlink traffic channel (DL.TCH) assignment in an exemplary downlink traffic control channel (DL.TCCH), in accordance with various embodiments. 
       FIG. 8  comprising the combination of  FIG. 8A ,  FIG. 8B  and  FIG. 8C  is a table of an exemplary specification of uplink traffic channel (UL.TCH) assignment in an exemplary downlink traffic control channel (DL.TCCH), in accordance with various embodiments. 
       FIG. 9  is a drawing illustrating the exemplary base station and exemplary wireless terminal of  FIG. 5  while downlink framing format is in use for the assignment signaling. 
       FIG. 10  is a drawing illustrating the exemplary base station and exemplary wireless terminal of  FIG. 5  while uplink framing format is in use for the assignment signaling. 
       FIG. 11  comprising the combination of  FIG. 11A ,  FIG. 11B  and  FIG. 11C  is a drawing of a flowchart of an exemplary method of operating a base station in accordance with various embodiments. 
       FIG. 12  is a flowchart of an exemplary method of operating a base station in accordance with various embodiments. 
       FIG. 13  is a flowchart of an exemplary method of operating a wireless terminal in accordance with various embodiments. 
       FIG. 14  is a drawing of an exemplary base station implemented in accordance with various embodiments. 
       FIG. 15  is a drawing of an exemplary wireless terminal, e.g., mobile node, implemented in accordance with various embodiments. 
       FIG. 16 ,  FIG. 17  and  FIG. 18  illustrate exemplary state transition signaling, traffic channel assignment signaling and recurring channel structure in accordance with various embodiments. 
   

   DETAILED DESCRIPTION 
     FIG. 1  shows an exemplary communication system  100  implemented in accordance with various embodiments. Exemplary communications system  100  includes multiple cells: cell  1   102 , cell M  104 . Exemplary system  100  is, e.g., an exemplary multiple access orthogonal frequency division multiplexing (OFDM) wireless communications system such as a multiple access OFDM spread spectrum system including tone hopping. Each cell  102 ,  104  of exemplary system  100  includes three sectors. Cells which have not be subdivided into multiple sectors (N=1), cells with two sectors (N=2) and cells with more than 3 sectors (N&gt;3) are also possible in accordance with various embodiments. Each sector supports one or more carriers and/or downlink tones blocks. Each downlink tone block has a corresponding uplink tone block. In some embodiments at least some of the sectors support three downlink/uplink tones block pairs. Each combination of a sector and tone block pair, for a base station, corresponds to a different base station sector attachment point. Cell  102  includes a first sector, sector  1   110 , a second sector, sector  2   112 , and a third sector, sector  3   114 . Similarly, cell M  104  includes a first sector, sector  1   122 , a second sector, sector  2   124 , and a third sector, sector  3   126 . Cell  1   102  includes a base station (BS), base station  1   106 , and a plurality of wireless terminals (WTs) in each sector  110 ,  112 ,  114 . Sector  1   110  includes WT( 1 )  136  and WT(N)  138  coupled to BS  106  via wireless links  140 ,  142 , respectively; sector  2   112  includes WT( 1 ′)  144  and WT(N′)  146  coupled to BS  106  via wireless links  148 ,  150 , respectively; sector  3   114  includes WT( 1 ″)  152  and WT(N″)  154  coupled to BS  106  via wireless links  156 ,  158 , respectively. Similarly, cell M  104  includes base station M  108 , and a plurality of wireless terminals (WTs) in each sector  122 ,  124 ,  126 . Sector  1   122  includes WT( 1 ″″)  168  and WT(N″″)  170  coupled to BS M  108  via wireless links  180 ,  182 , respectively; sector  2   124  includes WT( 1 ′″″)  172  and WT(N′″″)  174  coupled to BS M  108  via wireless links  184 ,  186 , respectively; sector  3   126  includes WT( 1 ″″″)  176  and WT(N″″″)  178  coupled to BS M  108  via wireless links  188 ,  190 , respectively. 
   System  100  also includes a network node  160  which is coupled to BS 1   106  and BS M  108  via network links  162 ,  164 , respectively. Network node  160  is also coupled to other network nodes, e.g., other base stations, AAA server nodes, intermediate nodes, routers, etc. and the Internet via network link  166 . Network links  162 ,  164 ,  166  may be, e.g., fiber optic cables. Each wireless, e.g. WT  1   136 , includes a transmitter as well as a receiver. At least some of the wireless terminals, e.g., WT( 1 )  136 , are mobile nodes which may move through system  100  and may communicate via wireless links with the base station in the cell in which the WT is currently located, e.g., using a base station sector attachment point. The wireless terminals (WTs), e.g. WT( 1 )  136 , may communicate with peer nodes, e.g., other WTs in system  100  or outside system  100  via a base station, e.g. BS  106 , and/or network node  160 . WTs, e.g., WT( 1 )  136  may be mobile communications devices such as cell phones, personal data assistants with wireless modems, laptop computers with wireless modems, data terminals with wireless modems, etc. 
   In the exemplary system  100  of  FIG. 1 , corresponding to each base station attachment point, there is a recurring downlink/uplink channel structure which includes traffic channel assignment signaling opportunities and traffic channel segments. The assignment signaling opportunities, e.g., traffic control channel segments including one or more assignment opportunities, are linked to corresponding traffic channel segments. This predetermined linkage between an assignment signaling opportunity in the structure and a traffic channel segment in the structure reduces overhead signaling. In accordance with various embodiments, the assignment opportunities have, on an individual basis, a fixed association with one or more of a plurality of wtOnMask identifiers. For assignment opportunities where more than one wtOnMask identifier, representing a split-tone format, are possible alternatives, the assignment message includes a field, e.g., a single bit indicator field, used to distinguish between the alternatives. Thus a traffic channel segment can be unambiguously assigned to a wireless terminal. In this exemplary embodiment, a traffic channel segment can be assigned to any of the attachment points On state wireless terminals using full-tone dedicated control channel (DCCH) format, while the same traffic channel segment can be assigned to a subset of the wireless terminals using split-tone DCCH format. The approach, in accordance with various embodiments, provides an efficient, yet flexible assignment structure. 
     FIG. 2  is a drawing of an exemplary base station  200 , e.g., access node, implemented in accordance with various embodiments. Exemplary base station  200  may be any of the base stations ( 106 ,  108 ) of  FIG. 1 . Base station  200  includes a receiver module  202 , a transmitter module  204 , a processor  206 , an I/O interface  208 , and memory  210  coupled together via bus  212  over which the various elements may interchange data and information. Memory  210  includes routines  218  and data/information  240 . The processor  206 , e.g., a CPU, executes the routines  218  and uses the data/information  240  in memory  210  to control the operation of the base station and implement methods. 
   Receiver module  202 , e.g., an OFDM receiver, is coupled to receive antenna  203  via which the base station receives uplink signals from wireless terminals. Received uplink signals include requests for state transition, uplink control channel segment signals including uplink dedicated control channel segment signals, and uplink traffic channel segment signals. Receiver module  202  includes a decoder  214  for decoding at least some of the received uplink signals, e.g., performing a block decoding operation on received uplink signals corresponding to an uplink traffic channel segment. 
   Transmitter module  204 , e.g., an OFDM transmitter, is coupled to transmit antenna  205  via which the base station transmits downlink signals to wireless terminals. The downlink signals include state transition messages, downlink traffic control channel segment signals, and downlink traffic channel segment signals. At least some of the state transition messages include information indicating a wireless terminal On identifier and a wtOnMask. Downlink traffic control channel segment signals including assignment messages corresponding to uplink and/or downlink traffic channel segments, at least some of said assignment messages including a wtOnMask indicator value. Downlink traffic channel segment signals convey user data, e.g., voice data, audio data, text data, image data, file data, etc. In some embodiment, the same antenna is used for both receiver module  202  and transmitter module  204 , e.g., in conjunction with a duplex module. In various embodiments, there is a separate receiver module  202  and a separate transmitter module  204  corresponding to each sector of the base station, e.g., with separate antennas and/or a sectorized antenna. 
   I/O interface  208  couples the base station  200  to the Internet and/or other network nodes, e.g., other base stations, AAA server nodes, home agent nodes, routers, etc. The I/O interface  208  couples base station  200  to a backhaul network which couples various base stations together. Thus a wireless terminal coupled via a wireless connection to a first base station may have a communications session with another wireless terminal coupled by a wireless connection to a second base station. 
   Routines  218  include communications routines  222  and base station control routines  224 . The communications routines  222  implement the various communications protocols used by the base station  200 . The base station control routines  224  include a scheduling module  226 , an assignment signal generation module  228 , a dedicated control channel (DCCH) module  234 , a transmitter control module  236 , and a receiver control module  238 . 
   Scheduling module  226 , e.g., a scheduler, schedules wireless terminals using the base station to uplink and downlink traffic channel segments, e.g., based on scheduling protocol rules being used by base station  200 . For example, rules may take into account priority level, latency consideration, type of information to be communicated, request, channel conditions, interference levels, power considerations, amount of information to be communicated, and/or other factors when determining which user gets assigned which traffic channel segment. Scheduling module  226  associates wireless terminals with assignment slots in the channel structure. An assignment slot in the downlink traffic control channel is associated with a corresponding traffic channel segment in the channel structure in accordance with information  248  and/or information  250 . The association performed by scheduling module  226 , on a per segment basis, includes assigning a wireless terminal On state identifier and a wtOnMask identifier with an assignment slot. 
   Assignment signal generation module  228  uses the information output from the scheduling module  226  and uses the assignment message framing information and DL/UL timing/frequency structure information  244  to generate assignment signals. Assignment signal generation module  228  includes a flash channel sub-module  230  and a regular channel sub-module  232 . Flash channel sub-module  230  generates flash assignment signals to be conveyed over downlink traffic control channel flash segments, a flash assignment signal including an assignment message corresponding to a single traffic channel segment. Regular channel sub-module  232  generates regular assignment signals to be conveyed over downlink traffic control channel regular segments, a regular signal including an assignment message corresponding to up to three different traffic channel segments, each having a separate assignment. 
   DCCH module  234  controls the partitioning of the logical dedicated control channel tones between full-tone format tones and split tone format tones. The DCCH module  234  also decides which wireless terminals receive a DCCH tone in full-tone format and which receive a DCCH tone in split-tone format. DCCH module  234  generates state transition messages. At least some of the state transition messages are messages indicating a wireless terminal On state identifier and an assigned wtOnMask. For example, in an exemplary embodiment including 31 DCCH logical tones correspond to a base station attachment point and wherein in split tone format up to 3 wireless terminals may be assigned to use the same DCCH logical tone, the wireless terminal is assigned a 5 bit wireless terminal identifier and a three bit wtOnMask, a wtOnMask=111 indicates that the wireless terminal is to use the DCCH tone corresponding to the assigned On state identifier in full tone format, a wtOnMask=100, 010, or 001 indicates that the wireless terminal is to use the DCCH tone corresponding to the assigned On state identifier in split tone format. In addition the assigned wtOnMask is utilized in the assignment structure and assignment signaling. In an exemplary embodiment, one of four possibilities for an assigned wtOnMask (111, 001, 010, 100) for a given wireless terminal for a given connection is communicated via a 2 bit wide field in a state transition message directed to the wireless terminal. 
   Transmitter control module  236  controls operation of transmitter module  204 , while receiver control module  238  controls operation of receiver module  202 . 
   Data/information  240  includes system data/information  242 , wireless terminal data/information  268 , a plurality of sets of state transition message information (state transition message 1 information  256 , . . . state transition message n information  258 ), a plurality of sets of flash assignment message information (flash assignment message 1 information  260 , . . . , flash assignment message N information  262 ), and a plurality of sets of regular assignment message information (regular assignment message 1 information  264 , . . . , regular assignment message N information  266 ). 
   System data  242  includes downlink/uplink timing frequency structure information  244  and assignment message framing information  246 . Downlink/uplink timing/frequency structure information  244  includes recurring channel structure information, uplink and downlink tone block information, carrier frequency information, OFDM symbol timing information, information relating to grouping of OFDM symbols such as halfslots, slots, superslots, beaconslots, utlraslots, etc., and uplink and downlink tone hopping information. Downlink/uplink timing/frequency structure information  244  includes information relating the downlink traffic control channel to downlink traffic channel  248  and information relating the downlink traffic control channel to the uplink traffic channel  250 . Information  248  includes wireless terminal On Mask information  252 , e.g., information associating specific downlink traffic channel segments with specific assigned wtOnMasks and/or assigned wtOnMask Indicator values. Information  250  includes wireless terminal On Mask information  254 , e.g., information associating specific downlink traffic channel segments with specific assigned wtOnMasks and/or assigned wtOnMask Indicator values. 
   Assignment message framing information  246  includes information pertaining to the various types of assignment messages, e.g., flash assignment using uplink framing format, regular assignment using uplink framing format, flash assignment using downlink framing format, regular assignment using downlink framing format. 
   WT data/information  268  includes a plurality of sets of wireless terminal data/information (wireless terminal  1  data/information  270 , . . . , wireless terminal N data/information  272 ). Wireless terminal  1  data/information  270  includes an On state identifier  274 , an assigned wireless terminal On Mask  276 , a dedicated control channel mode  278 , user/device/session/resource information  280 , base station attachment point information  282 , user data  284 , and assigned traffic channel segment information  286 . 
   On state identifier  276  is the On state identifier assigned by the DCCH module to WT 1 , e.g., a 5 bit value in the range of 1 . . . 31. Assigned wtOnMask  276  is the wtOnMask assigned by DCCH module to WT 1 , e.g., a three bit value being one of 111, 100, 010, or 001. DCCH mode  278  is one of a DCCH full-tone format mode, e.g., corresponding to an assigned wtOnMask=111, and a DCCH split tone format mode, e.g., corresponding to any of assigned wtOnMask=100, 010, or 001. On state identifier  274  and assigned wtOnMask  276  are communicated via a state transition message, e.g., corresponding to one of (state transition message 1 info  256 , . . . , state transition message n information  258 ). 
   User/device/session/resource information  280  includes identification information and user profile information corresponding to the user of WT 1 , WT 1  device identification information, WT 1  device type information, WT 1  device parameter information, session information including peer node information, state information, routing information, session state information, and resource information such as uplink and/or downlink segments assigned to WT 1 . Base station attachment point information  282  includes information associating WT 1  with a particular base station attachment point corresponding to a base station sector and uplink/downlink tone block pair. User data  284  includes, e.g., voice data, audio data, image data, text data, file data, etc. User data  284  includes user data to be communicated in downlink traffic channel segments to WT 1 , received user data intended to be communicated to WT 1 , and user data sourced from WT 1  intended to be communicated to another peer node. Assigned traffic channel segment information  286  includes information identifying the uplink and/or downlink traffic channel segments that are assigned to WT 1 . 
   In some embodiments various modules and/or information in base station  200  are implemented on a per sector basis or per attachment point basis. 
     FIG. 3  is a drawing of an exemplary wireless terminal  300 , e.g., mobile node, implemented in accordance with various embodiments. Exemplary wireless terminal  300  may be any of the exemplary wireless terminals of exemplary system  100  of  FIG. 1 . Wireless terminal  300  includes a receiver module  302 , a transmission module  304 , a processor  306 , user I/O devices  308 , and memory  310  coupled together via a bus  312  via which the various elements can interchange data and information. Memory  310  includes routines  318  and data/information  320 . The processor  306 , e.g., a CPU, executes the routines  318  and uses the data/information  320  in memory  310  to control the operation of the wireless terminal  300  and implement methods. 
   Receiver module  302 , e.g., an OFDM receiver, is coupled to receive antenna  303  via which the wireless terminal  300  receives downlink signals from base stations. The downlink signals include state transition messages, downlink traffic control channel segment signals, and downlink traffic channel segment signals. At least some of the state transition messages include information indicating a wireless terminal On identifier and a wtOnMask. Downlink traffic control channel segment signals including assignment messages corresponding to uplink and/or downlink traffic channel segments, at least some of said assignment messages including a wtOnMask indicator value. Downlink traffic channel segment signals convey user data, e.g., voice data, audio data, text data, image data, file data, etc. Receiver module  303  includes a decoder  314  which decodes at least some of the received downlink signals. 
   Transmission module  304 , e.g., an OFDM transmitter, is coupled to transmit antenna  305  via which the wireless terminal transmits uplink signals to base stations. Transmitted uplink signals include requests for state transition, uplink control channel segment signals including uplink dedicated control channel segment signals, and uplink traffic channel segment signals. Transmission module  304  includes an encoder  316  which encodes at least some uplink signals prior to transmission. In some embodiments, the same antenna is used for the receiver module  302  and transmission module  304 , e.g., in conjunction with a duplex module. 
   User I/O devices  308 , e.g., microphone, keypad, keyboard, switches, camera, speaker, display, etc., allows a user of WT  300  to input user data, output user data, and control applications. In addition user I/O devices  308  allows the operator of WT  300  to control various functions of the WT  300 , e.g., initiate a communications session. 
   Routines  318  include a communications routine  322  and wireless terminal control routines  324 . The communications routine  322  implements the various communications protocols used by the wireless terminal  300 . Wireless terminal control routines  324  include an assignment signal processing module  326 , a dedicated control channel module  328 , a transmitter control module  330 , and a receiver control module  332 . 
   Assignment signal processing module  326  processes received assignment signals and determines whether or not a received assignment is intended for WT  300 . Assignment signal processing module  326  includes a flash assignment channel sub-module  334  for use when operating WT  300  in a full-tone format DCCH mode of operation, a flash assignment channel sub-module  336  for use when operating WT  300  in a split-tone format DCCH mode of operation, a regular assignment channel sub-module  338  for use when operating WT  300  in a full-tone format DCCH mode of operation, and a regular assignment channel sub-module  340  for use when operating WT  300  in a split-tone format DCCH mode of operation. 
   DCCH module  328  processes received state information messages. At least some of the received state transition messages are messages indicating an assigned wireless terminal is assigned a wireless terminal On state identifier and an assigned wtOnMask In one exemplary embodiment, the state transition message include a 5 bit wide field for the assigned wireless terminal identifier and a two bit wide field to convey one of four wtOnMask values. For example, in an exemplary embodiment including 31 DCCH logical tones correspond to a base station attachment point and wherein in split tone format up to 3 wireless terminals may be assigned to use the same DCCH logical tone, the wireless terminal is assigned a 5 bit wireless terminal identifier and a three bit wtOnMask, a wtOnMask=111 indicates that the wireless terminal is to use the DCCH tone corresponding to the assigned On state identifier in full tone format, a wtOnMask=100, 010, or 001 indicates that the wireless terminal is to use the DCCH tone corresponding to the assigned On state identifier in split tone format. In addition the assigned wtOnMask is utilized in the assignment structure and assignment signaling. DCCH module  328  determines the On state identifier  356  that WT  300  has been assigned to use, and the assigned WT On Mask  358  that the WT  300  has been assigned to use. From the received information, the WT  300  determines the DCCH mode  360 , e.g., whether it is to operating a full-tone format DCCH mode of operation or a split-tone format DCCH mode of operation. The determination of DCCH module  328  controls whether assignment signal processing sub-module pair ( 334 ,  338 ) are used in the case of full-tone DCCH mode, or whether assignment signal processing sub-module pair ( 336 ,  340 ) are used in the case of split-tone format DCCH mode operation. 
   Transmitter control module  330  controls operation of transmission module  304 , while receiver control module  332  controls operation of receiver module  302 . 
   Data/information  320  includes user/device/session/resource information  342 , system data/information  344 , received state transition message information  346 , a plurality of received flash assignment message information sets (received flash assignment message 1 information  348 , . . . , received flash assignment message N information  350 ), a plurality of received regular assignment message information sets (received regular assignment message 1 information  352 , . . . , received regular assignment message N information  354 ), an On state identifier  356 , an assigned wireless terminal On Mask  358 , a dedicated control channel mode  360 , base station attachment point information  362 , user data  366 , and assigned traffic channel segment information  368 . 
   User/device/session/resource information  342  includes identification information and user profile information corresponding to the user of WT  300 , WT  300  device identification information, WT  300  device type information, WT  300  device parameter information, session information including peer node information, state information, routing information, session state information, and resource information such as uplink and/or downlink segments assigned to WT  300 . Base station attachment point information  362  includes information associating WT  300  with a particular base station attachment point corresponding to a base station sector and uplink/downlink tone block pair. User data  366  includes, e.g., voice data, audio data, image data, text data, file data, etc. User data  366  includes user data received from downlink traffic channel segments assigned to WT  300 , and user data that WT  300  intends to transmit to a base station via an uplink traffic channel segment assigned to WT  300 , the data be subsequently communicated to another peer node of WT  300  in a communications session with WT  300 . Assigned traffic channel segment information  368  includes information identifying the uplink and/or downlink traffic channel segments that are assigned to WT  300 . 
   System data/information  344  includes a plurality of sets of base station data/information (base station  1  data/information  370 , base station M data/information  372 . Base station  1  data/information  370  includes downlink/uplink timing/frequency structure information  374  and assignment message framing information  376 . Downlink/uplink timing/frequency structure information  374  includes recurring channel structure information, uplink and downlink tone block information, carrier frequency information, OFDM symbol timing information, information relating to grouping of OFDM symbols such as halfslots, slots, superslots, beaconslots, utlraslots, etc., and uplink and downlink tone hopping information. DL/UL timing/frequency structure information  374  also includes information relating the downlink traffic control channel to the downlink traffic channel  378  and information relating the downlink traffic control channel to the uplink traffic channel  380 . Information  378  includes wireless terminal On Mask information  382 , e.g., information associating specific downlink traffic channel segments with specific assigned wtOnMasks and/or assigned wtOnMask Indicator value. Information  380  includes wireless terminal On Mask information  384 , e.g., information associating specific downlink traffic channel segments with specific assigned wtOnMasks and/or assigned wtOnMask Indicator values. 
   Assignment message framing information  376  includes information pertaining to the various types of assignment messages, e.g., flash assignment using uplink framing format, regular assignment using uplink framing format, flash assignment using downlink framing format, regular assignment using downlink framing format. 
   Received flash assignment message 1 information  348  includes information pertaining to a received flash assignment message, e.g., information input to and information recovered from one of modules  334  and  336 . Received regular assignment message 1 information  352  includes information pertaining to a received regular assignment message, e.g., information input to and information recovered from one of modules  338  and  334 . 
     FIG. 4  includes an exemplary base station  402  and a plurality of exemplary wireless terminals (WT  1   404 , . . . WT N  405 ) implemented in accordance with various embodiments. Exemplary base station  402  may be any of the exemplary base stations of  FIG. 1  and exemplary wireless terminals  404 ,  405  may be any of the exemplary wireless terminals of  FIG. 1 . Exemplary base station  402  transmits a state transition message  406  to wireless terminal  404 , the state transition message  406  including a WT On identifier  408  and a wtOnMask  410 . Exemplary base station  402  also transmits a state transition message  407  to wireless terminal  405 , the state transition message  407  including a WT On identifier  409  and a wtOnMask  411 . 
   Exemplary base station  402  uses a set of dedicated control channel tones (DCCH channel tone  1   412 , . . . , DCCH channel tone  31   414 ), each tone associated with a WT ON identifier. In this exemplary embodiment, WTs can be commanded to operate in either a full-tone DCCH mode or a split tone DCCH mode. In the full tone DCCH mode, the WT receives a WT ON identifier in the range of (1 . . . 31) and a wtOnMask=111. For example, corresponding to DCCH channel tone  1  in full-tone format, the WT ON ID=1  416  and the wtOnMask=111  418 . Similarly, corresponding to DCCH channel tone  31  in full-tone format, the WT ON ID=31  420  and the wtOnMask=111  422 . In the split-tone DCCH mode, a WT receives a WT ON identifier in the range of (1 . . . 31) and a wtOnMask equal to one of: 001, 010, or 100. In the split tone mode the same logical DCCH channel tone can be associated with up to three different WTs. For example, corresponding to DCCH channel tone  1  in split tone format, a first WT can be sent a state transition message including WT ON ID=1  424  and the wtOnMask=001  426 , a second WT can be sent a state transition message including WT ON ID=1  428  and the wtOnMask=010  430 , and a third WT can be sent a state transition message including WT ON ID=1  432  and the wtOnMask=100  434 . Similarly corresponding to DCCH channel tone  31  in split tone format, a first WT can be sent a state transition message including WT ON ID=31  436  and the wtOnMask=001  438 , a second WT can be sent a state transition message including WT ON ID=31  440  and the wtOnMask=010  442 , and a third WT can be sent a state transition message including WT ON ID=31  444  and the wtOnMask=100  446 . 
   In some embodiments, in the state transition message the wireless terminal On identifier is communicated via a 5 bit wide field and the wireless terminal ON mask is communicated via a two bit wide field. 
     FIG. 5  is a drawing  500  including an exemplary base station  502  and an exemplary wireless terminal  504 , implemented in accordance with various embodiments. Exemplary base station  502  may be any of the exemplary base stations of  FIG. 1  and exemplary wireless terminal  504  may be any of the exemplary wireless terminals of  FIG. 1 . Exemplary base station  502  transmits flash traffic channel assignment messages  506  and regular traffic channel assignment messages  508 . For example, in some embodiments the uplink and downlink traffic channel corresponding to base station  502  for a particular attachment point, e.g., sector and tone block, are partitioned into indexed segments in a repetitive pattern. In some embodiments there is a predetermined timing relationship between the assignments messages and the corresponding traffic channel segments which are assigned. 
   In this exemplary embodiment, each flash traffic channel assignment message  506  corresponds to one traffic channel segment and includes a WT On ID field of 5 bits  510  used to identify the WT to which the assignment is directed. The traffic channel segment being assigned by flash TCH assignment message  506  is one of an uplink traffic channel segment and a downlink traffic channel segment. 
   In this exemplary embodiment, each regular traffic channel segment assignment message  508  corresponds to three different traffic channel segments and includes first assignment information  512 , second assignment information  518 , and third assignment information  524 . First assignment information  512  includes a WT On ID (5 bits)  514  and a wtOnMask Identifier (1 bit)  516 . Second assignment information  518  includes a WT On ID (5 bits)  520  and a wtOnMask Identifier (1 bit)  522 . Third assignment information  524  includes a WT On ID (5 bits)  526  and a wtOnMask Identifier (1 bit)  528 . Each regular traffic channel assignment message is used to convey traffic channel segment assignments for one of the following: (i) two downlink traffic channel segments and one uplink traffic channel segments and (ii) one downlink traffic channel segment and two uplink traffic channel segments. 
     FIG. 6  comprising the combination of  FIG. 6A ,  FIG. 6B , and  FIG. 6C  is a flowchart  600  of an exemplary method of operating a wireless terminal in accordance with various embodiments. Operation of the exemplary method starts in step  602  where the wireless terminal is powered up and initialized. Operation proceeds from step  602  to step  604 , in which the wireless terminal receives a state transition message communicating a WT on identifier and a wtOnMask. For example, the status transition message is transmitted by a base station sector attachment point. For example, the base station sector attachment point uses a downlink tone block and a corresponding uplink tone block, and can support On state connections with a plurality of wireless terminals simultaneously. The WT On identifier is a base station assigned identifier associating the WT with one of a plurality of dedicated control channel uplink logical tones. The wtOnMask, in the exemplary embodiment, is one of the following: 001, 010, 100, and 111. The patterns 001, 010, 100 signify that the WT is to be in a split-tone DCCH mode of operation. The pattern 111 signifies that the WT is to be in a full-tone DCCH mode. 
   Operation proceeds from step  604  to step  606 , in which the WT checks whether or not the communicated wtOnMask of the received state transition message directed to the WT indicates that the WT need not evaluate wtONMask assignment signal information to determine if an assigned traffic channel segment is for the WT. For example, if the communicated wtOnMask of the received state transition message is 111 the WT is to be in full-tone DCCH mode and need not evaluate the wtOn Mask Assignment signal information to determine if an assignment is for the WT, and operation proceeds from step  606  to step  608 . However, if the communicated wtOnMask of the state transition message is one of 001, 010, and 100 the WT is to be in split-tone DCCH mode and the WT evaluates the wtOn Mask Assignment signal information to determine if an assignment is for the WT, and operation proceeds from step  606  to step  616 . 
   In step  608 , the wireless terminal receives assignment messages. Operation proceeds from step  608  to step  610  for each received assignment message. In step  610  the wireless terminal proceeds along different paths depending upon whether the received assignment message is a flash assignment or a regular assignment. In some embodiments, flash assignments are communicated using a higher per tone transmission power on non-zero modulation symbols than used for regular assignment signals. In some embodiments, flash assignments include signaling using a combination of zero and non-zero modulation symbol values associated with the tone-symbols of a flash assignment channel segment, while a regular assignment channel segment uses non-zero modulation symbol values for each tone-symbol of the regular assignment channel segment. If the received assignment message is a flash assignment, operation proceeds from step  610  to subroutine  1   626 , via go to step  612 . If the received assignment message is a regular assignment, operation proceeds from step  610  to subroutine  2   650 , via go to step  614 , for each of a plurality of traffic channel assignments, e.g., three traffic channel assignments, included in the regular assignment message. 
   Exemplary subroutine  1   626 , used for determining whether or not a flash assignment of a traffic channel segment corresponds to the WT, will now be described. In step  628 , the WT determines a wtOnMask corresponding to the segment assignment from the segment position in a predetermined repetitive structure. For example, in one exemplary embodiment, the uplink traffic channel includes 28 indexed uplink traffic channel segments which are assigned via flash assignment signals. Considering the split-tone DCCH mode of operation, of those 28 uplink traffic channel segments, a first set of 10 uplink traffic channel segments may be individually assigned to a WT(s) with its wtOnMask set to 001, a second set of 9 uplink traffic channel segments may be individually assigned to a WT(s) with its wtOnMask set to 010, and a third set of 9 uplink traffic channel segments may be individually assigned to a WT(s) with its wtOnMask set to 100, the first, second, and third sets being non-overlapping sets. 
   For example, in one exemplary embodiment uplink traffic channel segments with index values (3, 13, 22, 30, 38, 47, 54, 61, 71, and 0) form the 1 st  set; uplink traffic channel segments with index values (6, 16, 25, 32, 39, 49, 57, 66, and 74) form the 2 nd  set; uplink traffic channel segments with index values (10, 19, 28, 35, 34, 52, 58, 68, and 76) form the 3 rd  set. In a similar way, the set of downlink traffic channel segments, which are assigned via flash assignments are partitioned among the three wtOnMask values that may be assigned to a WT in a split-tone DCCH mode of operation. 
   Operation proceeds from step  628  to step  630 . In step  630 , the WT compares the determined wtOnMask corresponding to the segment assignment with the wtOnMask from the state transition message. Operation proceeds from step  630  to step  632 . In step  632 , the WT determines whether the comparison indicates that the assigned segment may be the WT. For example, in the exemplary embodiment, if the wtOnMask from the transition message matches the wtOnMask corresponding to the segment assignment, that indicates that the assigned segment may be to the WT and operation proceeds from step  632  to step  634 ; otherwise the WT, in split tone DCCH mode, is precluded from being assigned the segment and operation proceeds from step  632  to step  640 . 
   In some embodiments, a WT in split tone DCCH mode may be assigned two portions of the DCCH channel tone, and such a WT may receive a wtOnMask=011, 101 or 110. In some such embodiments, a wtOnMask corresponding to the assignment signal is one of 001, 010, and 100, and the traffic channel segment may be assigned to the WT if a bit-wise logical AND of any of the same position bit in the wtOnMask of the transition message with the corresponding position bit in the wtOnMask representing the assignment message equals 1. For example, if the wtOnMask from the transition message is 011 and the wtOnMask representing the assignment message is 001 or 010, the WT may be assigned the segment; however, if the wtOnMask from the transition message is 011 and the wtOnMask representing the assignment message is 100, the WT is precluded from being assigned the segment. 
   In step  634 , the WT determines the WT On identifier corresponding to the segment assignment from information included in the assignment message, e.g., from a 5 bit WT On ID field. Operation proceeds from step  634  to step  636 . In step  636  the WT tests does the determined WT On identifier corresponding to the segment match the WT On identifier from the state transition message. If there is a match, the WT proceeds to step  638 , where subroutine  1  returns an indication that the assigned traffic channel segment is for the WT. If there is not a match, operation proceeds to step  640 . In step  640 , subroutine  1  returns an indication that the assigned traffic channel segment is not for the WT. 
   Exemplary subroutine  2   650 , used for determining whether or not a regular assignment of a traffic channel segment corresponds to the WT, will now be described. In step  652 , the WT determines two alternative wtOnMasks that may correspond to the segment assignment from the segment position in a predetermined repetitive structure. For example, in one exemplary embodiment, the uplink traffic channel includes 49 indexed uplink traffic channel segments which are assigned via regular assignment signals. Considering the split-tone DCCH mode of operation, of those 49 uplink traffic channel segments, a first set of 17 uplink traffic channel segments may be individually assigned to a WT(s) with its wtOnMask set to 001 or 010, a second set of 16 uplink traffic channel segments may be individually assigned to a WT(s) with its wtOnMask set to 010 or 100, and a third set of 16 uplink traffic channel segments may be individually assigned to a WT(s) with its wtOnMask set to 100 or 001, the first, second, and third sets being non-overlapping sets. For example, in one exemplary embodiment uplink traffic channel segments with index values (4, 8, 12, 17, 21, 26, 31, 36, 40, 45, 50, 55, 60, 64, 69, 73, and 2) form the 1 st  set; uplink traffic channel segments with index values (7, 11, 15, 20, 24, 29, 34, 41, 43, 48, 53, 59, 63, 67, 72, and 1) form the 2 nd  set; uplink traffic channel segments with index values (5, 9, 14, 18, 23, 27, 33, 37, 42, 46, 51, 56, 62, 65, 70, and 75) form the 3 rd  set. In a similar way, the set of downlink traffic channel segments, which are assigned via regular assignments are associated with wtOnMask values that may be assigned to a WT in a split-tone DCCH mode of operation. 
   Operation proceeds from step  652  to step  654 . In step  654 , the WT determines the wtOnMask corresponding to the segment assignment from information included in the assignment message. For example, a 1 bit wtOnMask Identifier bit included in the assignment message allows the base station to select between the two potential alternative wtOnMasks of step  652 . For example, consider that the assignment corresponds to exemplary uplink traffic channel segment with index value=4 and the two alternative wtOnMasks of step  652  are 001 and 010. If the wtOnMask Identifier bit included in the assignment message is 0, that indicates that the assigned wtOnMask=001; however if the wtOnMask Identifier bit included in the assignment message is 1, that indicates that the assigned wtOnMask=010. In step  656 , the WT compares the determined wtOnMask corresponding to the segment assignment with the wtOnMask from the state transition message. Operation proceeds from step  656  to step  658 . In step  658 , the WT determines whether the comparison indicates that the assigned segment may be the WT. For example, in the exemplary embodiment, if the wtOnMask from the transition message matches the wtOnMask corresponding to the segment assignment, that indicates that the assigned segment may be to the WT and operation proceeds from step  658  to step  660 ; otherwise the WT, in split tone DCCH mode, is precluded from being assigned the segment and operation proceeds from step  658  to step  666 . 
   In some embodiments, a WT in split tone DCCH mode may be assigned two portions of the DCCH channel tone, and such a WT may receive a wtOnMask=011, 101 or 110. In some such embodiments, a wtOnMask indicated in the assignment signal is one of 001, 010, and 100, and the traffic channel segment may be assigned to the WT if a bit-wise logical AND of any of the same position bit in the wtOnMask of the transition message with the corresponding position bit in the wtOnMask of the assignment message equals 1. For example, if the wtOnMask from the transition message is 011 and the wtOnMask representing the assignment message is 001 or 010, the WT may be assigned the segment; however, if the wtOnMask from the transition message is 011 and the wtOnMask representing the assignment message is 100, the WT is precluded from being assigned the segment. 
   In step  660 , the WT determines the WT On identifier corresponding to the segment assignment from information included in the assignment message, e.g., from a 5 bit WT On ID field. Operation proceeds from step  660  to step  662 . In step  662  the WT tests does the determined WT On identifier corresponding to the segment match the WT On identifier from the state transition message. If there is a match, the WT proceeds to step  664 , where subroutine  2  returns an indication that the assigned traffic channel segment is for the WT. If there is not a match, operation proceeds to step  666 . In step  666 , subroutine  2  returns an indication that the assigned traffic channel segment is not for the WT. 
   Returning to step  616 , in step  616  the WT receives assignment messages. For each traffic channel assignment included in the assignment message, operation proceeds from step  616  to step  618 . In step  618 , the WT determines the WT On identifier corresponding to the segment assignment from information included in the assignment message, e.g., from a 5 bit WT On ID field in the assignment message. Operation proceeds from step  618  to step  620 . In step  620 , the WT determines whether or not the determined WT On identifier corresponding to the segment matches the WT On identifier from the state transition message. If there is a match, the WT proceeds to step  620  to step  622 , where the WT recognizes that the assigned traffic channel segment is for the WT. If there is not a match, operation proceeds to step  624 . In step  624 , the wireless terminal recognizes that the assigned traffic channel segment is not for the WT. 
     FIG. 7  is a table  700  of an exemplary specification of downlink traffic channel (DL.TCH) assignment in an exemplary downlink traffic control channel (DL.TCCH). The information of table  700  may correspond to information relating DL.TCCH to DL.TCH  378  in wireless terminal  300  and information relating DL.TCCH to DL.TCH  248  in base station  200 . In Table  700  if an assignment field does not exist in the framing format, the corresponding entry is marked with “N/A”. An assigned DL.TCH segment is marked via shading, if it starts in the superslot that immediately follows the superslot of the assigning DL.TCCH segment. 
   First column  702  “row index” specifies a row index. For a given row index, a row specifies the indexes of the assigned DL.TCH segments and the information about the wtOnMask of the assigned DL.TCH segment. Second column  704  “framing format” specifies the framing format used in the downlink traffic control channel flash (DL.TCCH.FLASH) and downlink traffic control channel regular (DL.TCCH.REGULAR) segments for a given row index. 
   Third column  706  “index of assigned DL.TCH segment in DL.TCCH.FLASH” specifies the index of the DL.TCH segment assigned by the DL.TCCH.FLASH segment. 
   Fourth column  708  “assigned wtOnMask in DL.TCCH.FLASH” specifies the assigned wtOnMask to the DL.TCH segment in third column  706 . “s” denotes the segment index of the DL.TCCH.FLASH and the DL.TCCH.REGULAR segments in a given slot. In some embodiments s is an integer value in the range 0:63. 
   Fifth column  710  “index of assigned DL.TCH segment in DL.TCCH.REGULAR DL.TCH assignment 0” specifies the index of the DL.TCH segment assigned by the DL.TCH.assignment 0” field of the DL.TCCH.REGULAR segment. Sixth column  712  “assigned wtOnMask in DL.TCCH.REGULAR DL.TCH assignment 0” specifies the two possible wtOnMasks to be used in the DL.TCH segment specified in fifth column  710 . The “assigned wtOnMask” subfield of the “DL.TCH assignment field of the DL.TCCH.REGULAR segment specifies which one of the two possible wtOnMasks is actually assigned; if the “ON MASK” subfield is 0, the first one in sixth column  712  is the assigned wtOnMask to the DL.TCH segment; if the “ON MASK” subfield is 1, the second one in sixth column  712  is the assigned OnMask to the DL.TCH segment. 
   Seventh column  714  “index of assigned DL.TCH segment in DL.TCCH.REGULAR DL.TCH assignment 1” specifies the index of DL.TCH segment assigned by the “DL.TCH assignment 1” field of the DL.TCCH.REGULAR segment. Eighth column  716  “assigned wtOnMask in DL.TCCH.REGULAR DL.TCH assignment 1” specified the two possible wtOnMasks to be used in the DL.TCH segment specified in seventh column  714 . The “assigned wtOnMask” subfield of the “DL.TCH assignment field of the DL.TCCH.REGULAR segment specifies which one of the two possible wtOnMasks is actually assigned; if the “ON MASK” subfield is 0, the first one in eighth column  716  is the assigned wtOnMask to the DL.TCH segment; if the “ON MASK” subfield is 1, the second one in eight column  716  is the assigned OnMask to the DL.TCH segment. 
   Examples illustrating the use of table  700  will now be described. Consider s=6. Note that mod(s,8)=6, where s=6. Therefore check the row index=6. There is no DL.TCH assignment in the DL.TCCH.FLASH segment. The “DL.TCH assignment 0” field of the DL.TCCH.REGULAR segment specifies the assignment for DL.TCH segment [14] and either 0b001 or 0b010 can be the assigned wtOnMask to DL.TCH segment [14] depending on the “ON MASK” subfield of the “DL.TCH assignment 0” field. If the “ON MASK” subfield is 0, then the assigned wtOnMask is 0b001. Thus, the wtOnMask of the assigned WT can be either 0b001 or 0b111. If the “ON MASK” subfield is 1, then the assigned wtOnMask is 0b010. Thus, the wtOnMask of the assigned WT can be either 0b010 or 0b111. The “DL.TCH assignment 1” field of the DL.TCCH.REGULAR segment specifies the assignment for DL.TCH segment [15] and either 0b100 or 0b001 can be the assigned wtOnMask to DL.TCH segment [15] depending on the “ON MASK” subfield of the “DL.TCH assignment 1” field. If the “ON MASK” subfield is 0, then the assigned wtOnMask is 0b100. Thus, the wtOnMask of the assigned WT can be either 0b100 or 0b111. If the “ON MASK” subfield is 1, then the assigned wtOnMask is 0b001. Thus, the wtOnMask of the assigned WT can be either 0b001 or 0b111. 
   Now consider s=15. Note that mod(s,8)=7, where s=15. Therefore check the row index=7. DL.TCCH.FLASH and DL.TCCH.REGULAR segment [15] uses the downlink framing format. The “DL.TCH assignment 0” field of the DL.TCCH.FLASH segment specifies the assignment for DL.TCH [1] and the wtOnMask and the wtOnMask of the WT to be assigned to DL.TCH segment [1] is 1&lt;&lt;mod ((15-1)/2,3)=0b010, where the operator “&lt;&lt;” represents a bit-wise shift left. The “DL.TCH assignment 0” field of the DL.TCCH.REGULAR segment specifies the assignment for DL.TCH segment [0] and either 0b010 or 0b100 is the wtOnMask of the WT to be assigned to DL.TCH[0] depending on the “ON MASK” subfield of the “DL.TCH assignment 0” field. If the “ON MASK” subfield is 0, then the assigned wtOnMask is 0b010. Thus, the wtOnMask of the assigned WT can be either 0b010 or 0b111. If the “ON MASK” subfield is 1, then the assigned wtOnMask is 0b100. Thus, the wtOnMask of the assigned WT can be either 0b100 or 0b111. There is no “DL.TCH assignment 1” field. Note that the two DL.TCH segments both start in the superslot that immediately follows the superslot of the DL.TCCH segment. 
     FIG. 8  comprising the combination of  FIG. 8A ,  FIG. 8B  and  FIG. 8C  is a table  800  of an exemplary specification of uplink traffic channel (UL.TCH) assignment in an exemplary downlink traffic control channel (DL.TCCH). The information of table  800  may correspond to information relating DL.TCCH to UL.TCH  380  in wireless terminal  300  and information relating DL.TCCH to UL.TCH  250  in base station  200 . Table  800  shows the assignment of UL.TCH in a beaconslot. The pattern repeats every beaconslot. For s=0:63, the UL.TCH segments assigned by the DL.TCCH.FLASH segment [s] and DL.TCCH.REGULAR segment [s] are specified in the rows whose row index is equal to mod(s-floor(BSS_DLUL_OFFSET/14), 64), where BSS_DLUL_OFFSET is an non-negative integer value associated with the base station sector specifying how much time a downlink superslot leads its concurrent uplink superslot as measured at the base station sector. 
   In table  800 , if the UL.TCH segment corresponding to an assignment field is absent, the corresponding entry is marked with an “x”; if an assignment field itself does not exist in the framing format, the corresponding entry is marked with an “N/A”. 
   First column  802  “row index” specifies a row index. For a given row index, a row specifies the indexes of the assigned UL.TCH segments and the information about the wtOnMask of the WT assigned to a corresponding UL.TCH segment. Second column  804  “framing format” specifies the framing format used in the DL.TCCH.FLASH and DL.TCCH.REGULAR segments for a given row index. 
   Third column  806  “index of assigned UL.TCH segment in DL.TCCH.FLASH” specifies the index of the UL.TCH segment assigned by the DL.TCCH.FLASH segment. Fourth column  808  “assigned wtOnMask in DL.TCCH.FLASH” specifies the assigned wtOnMask to the UL.TCH segment specified in third column  806 . 
   Fifth column  810  “index of assigned UL.TCH segment in DL.TCCH.REGULAR UL.TCH assignment 0” specifies the index of UL.TCH segment assigned by the “UL.TCH assignment 0” field of the DL.TCCH.REGULAR segment. Sixth column  812  “assigned wtOnMask in DL.TCCH.REGULAR UL.TCH assignment 0” specifies two possible wtOnMasks to be used in the UL.TCH specified in fifth column  810 . The “ON MASK” subfield of the “UL.TCH assignment 0” field of the DL.TCCH.REGULAR segment specifies which of the two wtOnMasks is actually assigned; if the “ON MASK” subfield is 0, the first one in sixth column  812  is the wtOnMask of the WT assigned to the UL.TCH segment; if the “ON MASK” subfield is 1, the second one in column  812  is the wtOnMask of the WT assigned to the UL.TCH segment. 
   Seventh column  814  “index of assigned UL.TCH segment in DL.TCCH.REGULAR UL.TCH assignment 1” specifies the index of UL.TCH segment assigned by the “UL.TCH assignment 1” field of the downlink TCCH.REGULAR segment. Eighth column  816  “assigned wtOnMask in DL.TCCH.REGULAR UL.TCH assignment 1” specifies the two possible wtONMasks to be used in the UL.TCH segment specified in seventh column  814 . The “ON MASK” subfield of the “UL.TCH assignment 1” field of the DL.TCCH.REGULAR segment specifies which of the two wtOnMasks is actually assigned; if the “ON MASK” subfield is 0, the first one in eighth column  816  is the wtOnMask of the WT assigned to the UL.TCH segment; if the “ON MASK” subfield is 1, the second one in column 6 is the wtOnMask of the WT assigned to the UL.TCH segment. 
   Examples illustrating the use of table  800  will now be described. Consider s=63 and BSS_DLUL_OFFSET=33. Note that under those conditions, mod(s-floor(BSS_DLUL_OFFSET/14),64)=61. Therefore check the row of row index  61 . DL.TCCH.FLASH and DL.TCCH.REGULAR segment [63] uses the downlink framing format. There is no UL.TCH in the DL.TCCH.FLASH segment. The UL.TCH segments corresponding to the “UL.TCH assignment 0” and “UL.TCH assignment 1” fields of the DL.TCCH.REGULAR segment are both absent. The corresponding “ON MASK” subfields are set to N/A. 
   Now consider s=0, and BSS_DLUL_OFFSET=33. Note that under those conditions, where mod(s-floor(BSS_DLUL_OFFSET/14),64)=62. Therefore check the row of row index  62 . DL.TCCH.FLASH and DL.TCCH.REGULAR segment [0] uses the uplink framing format. The “UL.TCH assignment 0” field of the DL.TCCH.FLASH segment specifies the assignment for UL.TCH segment [0] and the assigned wtOnMask to UL.TCH segment [0] is 0b001. Thus the wtOnMask of the assigned WT can be either 0b001 or 0b111. The UL.TCH segment corresponding to “UL.TCH assignment 0” field of the DL.TCCH.REGULAR segment is absent. There is no “UL.TCH assignment 1” field. Note that the assigned UL.TCCH.REGULAR segment is absent. There is no “UL.TCCH assignment 1” field. Note that the assigned UL.TCH segment [0] starts in the same beaconslot as the assigning DL.TCCH segment [0]. 
   Now consider s=62, and BSS_DLUL_OFFSET=33. Note that under those conditions, where mod(s-floor(BSS DLUL_OFFSET/14),64)=60. Therefore check the row of row index  60 . DL.TCCH.FLASH and DL.TCCH.REGULAR segment [62] uses the uplink framing format. The “UL.TCH assignment 0” field of the DL.TCCH.FLASH segment specifies the assignment for UL.TCH segment [76] and the assigned wtOnMask to UL.TCH segment [0] is 0b100. Thus the wtOnMask of the assigned WT can be either 0b100 or 0b111. The “UL.TCH assignment 0” field of the DL.TCCH.REGULAR segment specifies the assignment for UL.TCH segment [75] and either 0b100 or 0b001 is the assigned wtOnMask to UL.TCH segment [75] depending on the “ON MASK” subfield of the “UL.TCH assignment 0” field. If the “ON MASK” subfield is 0, then the assigned wtOnMask is 0b100. Thus the wtONMask of the assigned WT can be either 0b100 or 0b111. If the “ON MASK” subfield is 1, then the assigned wtOnMask is 0b001. Thus the wtOnMask of the assigned WT can be either 0b001 or 0b111. There is no “UL.TCH assignment 1” field. Note that the two assigned UL.TCH segments both start in the same beaconslot as the assigning DL.TCCH segment. 
   The structure of an exemplary embodiment will be described. If uplink framing format is used, a DL.TCCH.FLASH channel segment conveys at most one uplink traffic channel assignment and no downlink traffic channel assignments. If uplink framing format is used, a DL.TCCH.REGULAR channel segment conveys at most two downlink traffic channel assignment and at most one uplink traffic channel assignment. 
   If downlink framing format is used, a DL.TCCH.FLASH channel segment conveys at most one downlink traffic channel assignment and no downlink traffic channel assignments. If downlink framing format is used, a DL.TCCH.REGULAR channel segment conveys at most one downlink traffic channel assignment and at most two uplink traffic channel assignment. 
   In this exemplary embodiment, within a beaconslot there are 64 flash assignment segments and 64 regular assignment segments, each assignment segment has a fixed mapping to one or more corresponding traffic channel segments in the structure, e.g., in accordance with the tables  700  and  800 . 
   Each flash traffic channel assignment is associated with a fixed one of the wtOnMasks corresponding to operation in DCCH split tone mode. Each regular traffic channel assignment can be associated with either of two wtOnMasks corresponding to operation in DCCH split tone mode. The regular assignment message corresponding to a regular traffic channel assignment includes a single bit OnMask indicator value to distinguish between the two possibilities. A wireless terminal operating in split tone mode needs to determine that both the On state identifier and the indicator mask bit indicate that the assignment is directed to itself. 
   A WT operating in full-tone mode need not use the OnMask indicator in determining that an assignment is directed to itself, the decoding of the ON state identifier included in the message is sufficient. 
     FIG. 9  is a drawing  900  illustrating the exemplary base station  502  and exemplary wireless terminal  504  of  FIG. 5  while downlink framing format is in use, as indicated by dashed box  901 , for the assignment signaling. Exemplary flash assignment message  906  for the traffic channel conveys an assignment for a corresponding downlink traffic channel segment. Exemplary flash assignment message  906  includes a 5 bit wireless terminal ON identifier value in an On identifier field of 5 bits  910 . Exemplary regular assignment message  908  for the traffic channel includes a first assignment  912  for a corresponding downlink traffic channel segment, a second assignment  918  for a corresponding uplink traffic channel segment, and a third assignment for a corresponding uplink traffic channel segment  924 . Each assignment (first  912 , second  918 , third  924 ) includes a 5 bit wireless terminal On identifier value of 5 bits in a On Identifier field of 5 bits ( 914 ,  920 ,  926 ) and a one bit wtOnMask Identifier value in an wtOn Mask Identifier field of one bit ( 916 ,  922 ,  928 ). 
   In some embodiments, for at least some of intervals in a recurring structure where downlink framing format is used, the regular assignment message  908  includes assignment opportunities for a predetermined subset of the first, second, and third assignments, e.g., as illustrated in the exemplary structure of Tables  700  and  800 . 
     FIG. 10  is a drawing  1000  illustrating the exemplary base station  502  and exemplary wireless terminal  504  of  FIG. 5  while uplink framing format is in use, as indicated by dashed box  1001 , for the assignment signaling. Exemplary flash assignment message  1006  for the traffic channel conveys an assignment for a corresponding uplink traffic channel segment. Exemplary flash assignment message  1006  includes a 5 bit wireless terminal ON identifier value in an On identifier field of 5 bits  1010 . Exemplary regular assignment message  1008  for the traffic channel includes a first assignment  1012  for a corresponding downlink traffic channel segment, a second assignment  1018  for a corresponding downlink traffic channel segment, and a third assignment for a corresponding uplink traffic channel segment  1024 . Each assignment (first  1012 , second  1018 , third  1024 ) includes a 5 bit wireless terminal On identifier value of 5 bits in a On Identifier field of 5 bits ( 1014 ,  1020 ,  1026 ) and a one bit wtOnMask Identifier value in an wtOn Mask Identifier field of one bit ( 1016 ,  1022 ,  1028 ). 
   In some embodiments, for at least some of intervals in a recurring structure where uplink framing format is used, the regular assignment message  1008  includes assignment opportunities for a predetermined subset of the first, second, and third assignments, e.g., as illustrated in the exemplary structure of Tables  700  and  800 . 
     FIG. 11  is a drawing of a flowchart  1100  of an exemplary method of operating a base station in accordance with various embodiments. The exemplary method starts in step  1102 , where the base station is powered on and initialized. Operation proceeds from start step  1102  to step  1104 , step  1122  via connecting node A  1106 , and step  1140  via connecting node B  1108 . 
   In step  1104 , the base station determines whether there are any wireless terminals to be transitioned to the On state of operation. For each such wireless terminal, operation proceeds from step  1104  to step  1110 . In step  1110 , the base station allocates a wireless terminal On state identifier, e.g., a 5 bit identifier, and a corresponding On state Mask value to the wireless terminal from available resources. Step  1110  includes steps  1112 ,  1114 ,  1116 , and  1118 . In step  1112 , the base station determines whether the wireless terminal is to operate in full tone dedicated control channel format mode or split tone dedicated control channel format mode. If the wireless terminal is to be operated in full-tone mode, operation proceeds from step  1112  to step  1114 ; if the wireless terminal is to be operated in split tone format mode operation proceeds from step  1112  to step  1116 . In step  1114 , the base station allocates the wireless terminal an On state identifier and an On Mask value=111. In the full tone format mode, the wireless terminal&#39;s base station assigned On state identifier is not shared with other wireless terminals with respect to the base station attachment point. In step  1116 , the base station allocates the wireless terminal a wireless terminal On state identifier and an On mask value which is one of: 001, 010, and 100. In the split tone format mode, the wireless terminal&#39;s base station assigned On state identifier may be and sometimes is shared with other wireless terminals with respect to the base station attachment point, e.g., three different wireless terminals in split tone mode may each be assigned the same On state identifier, but may be assigned different On masks. Operation proceeds from step  1114  or step  1116  to step  1118 . In step  1118 , the base station generates a state transition message including information communicating said wireless terminal On state identifier and said On state Mask value. 
   Operation proceeds from step  1110  to step  1120 . In step  1120 , the base station transmits said generated state transition message to said wireless terminal. Operation proceeds from step  1120  to step  1104 . 
   For each regular assignment signaling opportunity, operation proceeds via connecting node A  1106  to step  1122 . In step  1122 , the base station determines assignments for a regular traffic channel assignment message. Step  1122  includes steps  1124 ,  1126 ,  1128 ,  1130 ,  1132 ,  1134 , and  1136 . 
   In step  1124 , for a first traffic channel segment to be assigned, the base station selects a wireless terminal to receive the assignment, said wireless terminal corresponding to one of the wireless terminals in full tone format or a first subset of the set of wireless terminals in split tone format, said first subset including members whose assigned wireless terminal On Mask matches split tone assignment possibilities for the segment, e.g., a predetermined two of 001, 010, and 100. Operation proceeds from step  1124  to step  1126 . In step  1126 , the base station determines the wireless terminal ON state identifier corresponding to the selected wireless terminal of step  1124 , and if the selected wireless terminal is in split tone format, the base station determines a wireless terminal On Mask identifier, e.g., a 1 bit value which maps to the wireless terminal On Mask of the selected wireless terminal for the segment. 
   In step  1128 , for a second traffic channel segment to be assigned, the base station selects a wireless terminal to receive the assignment, said wireless terminal corresponding to one of the wireless terminals in full tone format or a second subset of the set of wireless terminals in split tone format, said second subset including members whose assigned wireless terminal On Mask matches split tone assignment possibilities for the segment, e.g., a predetermined two of 001, 010, and 100. Operation proceeds from step  1128  to step  1130 . In step  1130 , the base station determines the wireless terminal On state identifier corresponding to the selected wireless terminal of step  1128 , and if the selected wireless terminal is in split tone format, the base station determines a wireless terminal On Mask identifier, e.g., a 1 bit value which maps to the wireless terminal On Mask of the selected wireless terminal for the segment. 
   In step  1132 , for a third traffic channel segment to be assigned, the base station selects a wireless terminal to receive the assignment, said wireless terminal corresponding to one of the wireless terminals in full tone format or a third subset of the set of wireless terminals in split tone format, said third subset including members whose assigned wireless terminal On Mask matches split tone assignment possibilities for the segment, e.g., a predetermined two of 001, 010, and 100. Operation proceeds from step  1132  to step  1134 . In step  1134 , the base station determines the wireless terminal On state identifier corresponding to the selected wireless terminal of step  1132 , and if the selected wireless terminal is in split tone format, the base station determines a wireless terminal On Mask identifier, e.g., a 1 bit value which maps to the wireless terminal On Mask of the selected wireless terminal for the segment. 
   Operation proceeds from step  1126 ,  1130 , and  1134  to step  1136 , where the base station incorporates said determined information into a regular assignment message. Operation proceeds from step  1122  to step  1138 . In step  1138 , the base station transmits said regular assignment message at a predetermined time in a recurring downlink structure at a first power level. 
   For each flash assignment signaling opportunity, operation proceeds via connecting node B  1108  to step  1140 . In step  1140 , the base station determines an assignment for a flash traffic channel assignment message. Step  1140  includes steps  1142 ,  1144 , and  1146 . 
   In step  1142 , for a fourth traffic channel segment to be assigned, the base station selects a wireless terminal to receive the assignment, said wireless terminal corresponding to one of the wireless terminals in full tone format or a fourth subset of the set of wireless terminals in split tone format, said fourth subset including members whose assigned wireless terminal On Mask matches split tone assignment possibility for the segment, e.g., a predetermined one of 001, 010, and 100. Operation proceeds from step  1142  to step  1144 . In step  1144 , the base station determines the wireless terminal ON state identifier corresponding to the selected wireless terminal of step  1142 . Operation proceeds from step  1144  to step  1146 , where the base station incorporates said determined information from step  1144  into a flash assignment message. 
   Operation proceeds from step  1140  to step  1148 , in which the base station transmits said flash assignment message at a predetermined time in a recurring downlink structure at a second power level, said second power level being higher than said first power level. 
     FIG. 12  is a flowchart  1200  of an exemplary method of operating a base station in accordance with various embodiments. Operation starts step  1202 , where the base station is powered on and initialized. Operation proceeds from start step  1202  to step  1204 . In some embodiments, at some times, operation also proceeds from start step  1202  to step  1206 . 
   In step  1204 , the base station communicates a base station assigned wireless terminal identifier and a corresponding mask value to a wireless terminal, said mask value being represented by a first number of information bits. For example, the base station assigned wireless terminal identifier and corresponding mask value may be communicated via a state transmission message transmitted to the wireless terminal. 
   In step  1206 , when performed, the base station communicates the same base station assigned wireless terminal identifier and a different corresponding mask value to a second wireless terminal, said second wireless terminal being assigned the same base station assigned wireless terminal identifier to be used for concurrent segment assignment recovery identification operations. For example in one exemplary embodiment, in step  1204 , the base station may have communicated a 5 bit base station assigned On state wireless terminal identifier=00001 and a 3 bit On mask value=001 to the wireless terminal; and in step  1206 , the base station may have communicated a 5 bit wide base station assigned wireless terminal On state identifier=00001 and a 3 bit wide On mask value=010 to the second wireless terminal. Continuing with the example, alternatively, if in step  1204 , the base station had communicated a 5 bit base station assigned On state wireless terminal identifier=00001 and a 3 bit On mask value=111 to the wireless terminal, the second base station could not share the same base station assigned wireless terminal identifier, the On mask value=111 signifying that the wireless terminal is to be operated in a mode where it does not share its On state identifier with other wireless terminals using the base station attachment point. In some embodiments, where the On Mask value can be one of four possibilities, e.g., (111, 001, 010, 100), the assigned On Mask value is communicated via a pattern of a two bit wide field. 
   Operation proceeds from step  1204  to step  1208 . In step  1208 , the base station communicates a first type assignment message, e.g., a regular type assignment message, to said wireless terminal, said first type assignment message including said wireless terminal identifier and a mask identifier value. In some embodiments, the mask identifier value is represented by a second number of information bits, said second number being less than said first number. In one exemplary embodiment, the mask value is communicated in a two bit wide field while the mask identifier value is communicated in a one bit wide field. 
   In some embodiments, at some times, operation proceeds from step  1208  to step  1210 . In step  1210 , the base station communicates a second type assignment message, e.g., a flash type assignment message, to said wireless terminal, said second type assignment message including said wireless terminal identifier but not including a mask identifier value. In some embodiments, the first type assignment message is communicated at a lower power level than said second type assignment message. 
   In various embodiments, the first and second type assignment messages are traffic channel assignment messages. In some such embodiments for at least some first type assignment messages, the first type assignment message conveys assignments for a plurality of, e.g., two or three, traffic channel segments, one of said plurality of assignments being conveyed by said wireless terminal identifier and said mask identifier value; and the second type assignment message conveys an assignment for a single traffic channel segment. 
   In some embodiments, the mask value identifies potential traffic channel segments in a recurring traffic channel structure which may be assigned to said wireless terminal. In some such embodiments if said mask value matches a first predetermined pattern, e.g., 111, any traffic channel segment from a set of traffic channel segments in the recurring traffic channel structure may be assigned to the wireless terminal and if the mask matches a second predetermined pattern, e.g., 001, a first predetermined subset of said set of traffic channel segments may be assigned to said wireless terminal, and if said mask matches a third predetermined pattern, e.g., 010, a second predetermined subset of said traffic channel segments may be assigned to said wireless terminal. In some such embodiments, the first predetermined subset and second predetermined subset are partially overlapping. In some embodiments, if the mask value matches a fourth predetermined value, e.g., 100, a third predetermined subset of said set of traffic channel segments may be assigned to said wireless terminal, said third predetermined subset being partially overlapping with said first and second predetermined subsets. 
   In various embodiments, the mask identifier value is represented by a single information bit, said single information bit distinguishing between two mask values which may be associated with the segment. 
     FIG. 13  is a flowchart  1300  of an exemplary method of operating a wireless terminal in accordance with various embodiments. The exemplary method starts in step  1302 , where the wireless terminal is powered on and initialized. Operation proceeds from start step  1302  to step  1304 . In step  1304 , the wireless terminal receives a base station assigned wireless terminal identifier of a first value and a corresponding mask value from a base station, said mask value being represented by a first number of information bits. In some embodiments, the mask identifier value is represented by a second number of information bits, the second number being less than the first number. In one exemplary embodiment, the mask value which can take one of four possibilities, e.g., 111, 001, 010 and 100 is conveyed via a 2 bit wide field, and the mask identifier value is conveyed by a one bit wide field. In some embodiments, the mask value is conveyed via a 3 bit wide field and the mask identifier value is conveyed via a one bit wide field. Operation proceeds from step  1304  to step  1306 , and in some embodiments, to step  1316 . 
   In step  1306 , the wireless terminal receives a first type assignment message from said base station, said first type assignment message including a wireless terminal identifier and a mask identifier value. Operation proceeds from step  1306  to step  1308 . In step  1308 , the wireless terminal identifies from said received first type assignment message whether or not the assignment is directed to the wireless terminal. If the wireless determines in step  1308 , that an assignment of the message received in step  1306  is directed to the wireless terminal, operation proceeds from step  1308  to step  1310 . Operation also proceeds from step  1308  to step  1306 , to receive additional first type assignment messages. 
   In step  1310 , the wireless determines whether the assignment slot corresponds to an uplink or downlink traffic channel segment. If the assignment directed to the wireless terminal corresponds to an uplink traffic channel segment operation proceeds from step  1310  to step  1312 ; if the assignment directed to the wireless terminal corresponds to a downlink traffic channel segment, operation proceeds to step  1314 . In step  1312 , the wireless terminal transmits coded information using an uplink traffic channel segment associated with said received assignment by a predetermined association. In step  1314 , the wireless terminal receives coded information communicated via a downlink traffic channel segment associated with said received assignment by a predetermined association. 
   In step  1316 , the wireless terminal receives a second type assignment message, said second type assignment message including a wireless terminal identifier but not including a mask identifier value. Operation proceeds from step  1316  to step  1318 . In step  1318 , the wireless terminal identifies from said received second type assignment message whether or not the assignment is directed to the wireless terminal. For example, if the base station assigned wireless terminal identifier received in step  1304  matches the base station assigned wireless terminal identifier received in step  1316 , the assignment is directed to the wireless terminal. If the wireless determines in step  1318 , that an assignment of the message received in step  1316  is directed to the wireless terminal, operation proceeds from step  1318  to step  1320 . Operation also proceeds from step  1318  to step  1316 , to receive additional second type assignment messages. 
   In step  1320 , the wireless determines whether the assignment slot corresponds to an uplink or downlink traffic channel segment. If the assignment directed to the wireless terminal corresponds to an uplink traffic channel segment operation proceeds from step  1320  to step  1322 ; if the assignment directed to the wireless terminal corresponds to a downlink traffic channel segment, operation proceeds to step  1324 . In step  1322 , the wireless terminal transmits coded information using an uplink traffic channel segment associated with said received assignment by a predetermined association. In step  1324 , the wireless terminal receives coded information communicated via a downlink traffic channel segment associated with said received assignment by a predetermined association. 
   In some embodiments, wherein when said received mask value is one of a set of a plurality of predetermined mask values, said step  1308  of identifying whether of not said received assignment is directed to said wireless terminal includes: (i) determining whether said received base station assigned wireless terminal identifier from step  1304  matches said wireless terminal identifier in said received first type assignment message of step  1306  and (ii) determining whether said wireless terminal identifier in said received assignment message from step  1306  identifies the received mask value from step  1304 . In one exemplary embodiment, the set of a plurality of predetermined mask values is {001, 010, 100}. 
   In some embodiments, wherein when said received mask value is a first predetermined mask value, said first predetermined mask value being exclusive from said set of plurality of predetermined mask values, said step  1308  of identifying whether of not said received assignment is directed to said wireless terminal includes: determining whether said received base station assigned wireless terminal identifier from step  1304  matches said wireless terminal identifier in said received first type assignment message of step  1306 , said determination not requiring use of said mask identifier value received in said assignment message. In one exemplary embodiment, the first predetermined mask value=111 and the set of a plurality of predetermined mask values is {001, 010, 100}. 
   In some embodiments, the wireless terminal determines a subset of assignment messages to receive as a function of the received mask value from step  1304 . In some embodiments, the wireless terminal determines a subset of the assignment messages to receive as a function of the received mask value from step  1304 . For example, in one exemplary embodiment, if a wireless terminal receives a mask value in step  1304 =111, the wireless terminal should attempt to receive and recover each of the assignment signals since any assignment may be directed to the wireless terminal, e.g., the wireless terminal is in a full tone format DCCH mode of operation. Continuing with the example, if a wireless terminal receives a mask value being one of 001, 010, and 100 in step  1304 , the wireless can, and sometimes does, selectively receive and/or process assignment signals, since by a predetermined implemented structure some assignments can be directed to the wireless terminal, while others can not be directed to the wireless terminal. In some such embodiments, the wireless terminal can conserve resources, e.g., power, processing time, and/or memory usage, by limiting reception and/or recovery operation of assignment signals. 
   In some embodiments, if said received mask value from step  1304  matches a first predetermined pattern, e.g., 111, any traffic channel segment from a set of traffic channel segments in the recurring traffic channel structure may be assigned to the wireless terminal and wherein if the mask matches a second predetermined pattern, e.g., 001, a first predetermined subset of said set of traffic channel segments may be assigned to said wireless terminal, and wherein if said mask matches a third predetermined pattern, e.g., 010, a second predetermined subset of traffic channel segments may be assigned to said wireless terminal. In some such embodiments, the first predetermined subset and the second predetermined subset are partially overlapping. In some embodiments, if said mask matches a fourth predetermined pattern, e.g., 100, a third predetermined subset of said traffic channel segments may be assigned to said wireless terminal, said third predetermined subset being partially overlapping with said first and second predetermined subsets. 
     FIG. 14  is a drawing of an exemplary base station  1400  implemented in accordance with various embodiments. Exemplary base station  1400  may be any of the base stations of system  100  of  FIG. 1 . Exemplary base station  1400  includes a receiver module  1402 , a transmitter module  1404 , a processor  1406 , I/O devices  1408 , and a memory  1410  coupled together via a bus  1412  over which the various elements may interchange data and information. The memory  1410  includes routines  1418  and data/information  1420 . The processor  1406 , e.g., a CPU, executes the routines  1418  and uses the data/information  1420  in memory  1410  to control the operation of the base station and implement methods. 
   Receiver module  1402 , e.g., an OFDM receiver is coupled to receive antenna  1403  via which the base station receives uplink signals from wireless terminals. The uplink signals include, e.g., registration request signals, requests to change a state of operation, uplink dedicated control channel signals including requests for traffic channel resources, and uplink traffic channel segment signals. Receiver module  1402  includes a decoder  1414  for decoding at least some of the received uplink signals. 
   Transmitter module  1404 , e.g., an OFDM transmitter, is coupled to transmit antennas  1405  via which the base station transmits downlink signals to wireless terminals, the downlink signals include, e.g., timing/synchronization signals, control signals including control signals conveying base station assigned wireless terminal identifiers and mask values, e.g., state transition message signals, first type assignment signals, second type assignment signals, and downlink traffic channel segment signals. The transmitter module  1404  includes an encoder  1416  for encoding at least some downlink signals to be transmitted. 
   I/O interface  1408  couples the base station  1400  to other network nodes, e.g., other base stations, routers, AAA servers, home agent nodes, various servers, etc., and/or the Internet. I/O interface  1408  allows a wireless terminal using a base station  1400  attachment point to participate in a communications session with a peer node located in a different cell using an attachment point of a different base station. 
   Routines  1418  include communications routines  1422  and base station control routines  1424 . The communications routines  1422  implement the various communications protocols used by the base station  1400 . The base station control routines  1424  include a scheduler module  1426 , a wireless terminal control message generation module  1428 , a first type assignment message generation module  1430 , a second type assignment message generation module  1432 , a power level control module  1434 , and a wireless terminal operational mode management module  1436 . 
   Scheduler module  1426 , e.g., a scheduler, schedules uplink and downlink segments to wireless terminals in accordance with an implemented scheduling policy. The scheduling of module  1426  includes the scheduling of uplink and downlink traffic channel segments. At some times, some of the segments may be unavailable to be scheduled to certain wireless terminal using the base station attachment point, e.g., as a function of the mask value assigned to the wireless terminal. 
   Wireless terminal control message generation module  1428  generates message information directed to a wireless terminal, said message information including a base station assigned wireless terminal identifier and a corresponding mask value. In some embodiments, the base station assigned wireless terminal identifier and the corresponding mask value are communicated via the same message, e.g., a state transition message. In one such exemplary embodiment, the base station assigned wireless terminal is communicated by a 5 bit wide field and the corresponding mask value being communicated by a two bit wide field. In one such embodiment, the base station assigned identifier is a value in the range of 1 . . . 31, and the corresponding mask value communicated by the two bit wide field is one of four different three bit wide patterns: 111, 001, 010 and 100. Generated control message 1 information  1452  and generated control message N information  1454  represents output from module  1428 . 
   The wireless terminal control message generation module  1428 , at times, generates message information directed to a second wireless terminal including the same base station assigned wireless terminal identifier and different corresponding mask value, said wireless terminal and said second wireless terminal being assigned the same base station assigned wireless terminal identifier to be used for concurrent segment information recovery operations. For example, WT A may be assigned base station assigned wireless terminal identifier=00011 and mask=001, while WTB may be assigned wireless terminal identifier=00011 and mask=010. 
   First type assignment message generation module  1430  generates an assignment message of a first type including a wireless terminal identifier and a mask identifier value. In some embodiments, the mask value is represented by a first number of information bits and the mask identifier value is represented by a second number of information bits, said second number of information bits being less than said first number. For example, in one exemplary embodiment, the mask value field in a state transition message is two bits wide communicating one of four possibilities (bit pattern 111, bit pattern 001, bit pattern 010, or bit pattern 100), while the mask identifier field in a first type assignment message is one bit wide communicating one of two possibilities. In some embodiments, the first type assignment message is referred to as a regular assignment message. Message 1 information  1460  and message N information  1454  represent output from module  1430 . 
   Second type assignment message generation module  1432  generates a second type assignment message including a wireless terminal identifier but not including a mask identifier value. In some embodiments, the second type assignment message is referred to as a flash assignment message. Message 1 information  1476  and message N information  1480  represent output from module  1434 . 
   Power level control module  1434  performs power control including controlling the relative transmission powers of first type assignment messages and second type assignment messages such that said first type assignment messages are transmitted at a lower power level than second type assignment messages. Power level control module  1434  uses power level information  1446 . 
   Wireless terminal operational mode management module  1436 , manages the operational mode for a plurality of wireless terminals using the base station attachment point. Management module  1436  determines, e.g., from available resources, a base station assigned wireless terminal identifier and corresponding mask value to temporarily assign to a wireless terminal, e.g., a wireless terminal which is to be transitioned into an On state of operation, e.g., a state of operation in which the wireless terminal may be assigned uplink and/or downlink traffic channel segments. In this exemplary embodiment, the value of the mask determines whether the wireless terminal is in a first or second mode of On state operation with different amounts of resources being available in the different modes of On state operation. For example, in one exemplary embodiment, if the mask=111, the wireless terminal is transitioned into a full tone format mode of dedicated control channel operation, while if the mask is one of 001, 100, and 010, the wireless terminal is being transitioned into a split tone format mode of operation, with more resources being available in the full tone format than in the split tone format mode of operation. Determinations made by the management module  1436  are forwarded to the wireless terminal control message generation module  1428 . 
   Data/information  1420  includes stored traffic channel structure information  1438  which includes segment to mask association information (segment  1 /mask association information  1442 , . . . , segment M/mask association information  1444 ), stored assignment/traffic channel segment mapping information  1440 , and power level information  1446 . Some exemplary stored traffic channel structure information  1438  includes at least some of the information of  FIGS. 7 and 8 . For example, with regard to segment/mask association information consider the information of columns  806  and  808  for second type assignments, and consider the information of columns ( 810  and  812 ) and ( 814  and  816 ) for second type assignments. Some exemplary stored assignment/traffic segment mapping information  1440  includes at least some of the information of  FIGS. 7 and 8 . In the example of  FIGS. 7 and 8 , each traffic channel segment is associated with an assignment slot following a predetermined relationship. 
   Power level information  1446  includes power level information associated with the transmission power level of 1 st  type assignment information messages  1448  and power level information associated with the transmission power level of 2 nd  type assignment information messages  1450 . Data/information  1420  also includes generated control message information (generated control message 1 information  1452 , . . . generated control message N information  1454 ). Generated control message 1 information  1452  includes a base station assigned wireless terminal identifier  1456  and a corresponding mask value  1458 . 
   Data/information  1420  also includes generated 1 st  type assignment message information (generated 1 st  type assignment message message 1 information  1460 , . . . , generated 1 st  type assignment message message m information  1474 ). Generated 1 st  type assignment message message 1 information  1460  includes a wireless terminal identifier corresponding to a first assignment being conveying in the message  1462  and a corresponding mask identifier value corresponding to the first assignment being conveyed in the message  1464 . Generated 1 st  type assignment message message 1 information  1460  also includes in some embodiments at some times, a wireless terminal identifier corresponding to a second assignment being conveying in the message  1466  and a corresponding mask identifier value corresponding to the second assignment being conveyed in the message  1468 ; and/or a wireless terminal identifier corresponding to a third assignment being conveying in the message  1470  and a corresponding mask identifier value corresponding to the third assignment being conveyed in the message  1472 . 
   Data/information  1420  also includes a generated 2 nd  type assignment message information (generated 2 nd  type assignment message message 1 information  1476 , . . . , generated 2 nd  type assignment message message n information  1480 ). Generated 2 nd  type assignment message message 1 information  1476  includes a wireless terminal identifier  1478  corresponding to the assignment but does not include a mask identifier. The communicated wireless terminal identifier  1476  of the 2 nd  type assignment message either alone or in combination with stored timing structure information being sufficient for a wireless terminal to determined whether or not a 2 nd  type assignment is directed to itself. 
   Data/information  1420  also includes a plurality of sets of wireless terminal data/information (wireless terminal  1  data/information  1482 , . . . , wireless terminal K data/information  1484 ), e.g., a plurality of wireless terminal currently using a base station  1400  attachment point. Wireless terminal  1  data/information  1482  includes, e.g., user data pertaining to wireless terminal  1  communicated in uplink and/or downlink traffic channel segments, a base station assigned wireless terminal identifier temporarily assigned to WT  1 , a corresponding mask temporarily assigned to wireless terminal  1 , a mode of operation associated with the mask, e.g., a first mode of operation in which a larger number of traffic channel segments are available for allocation to WT  1  in comparison to a second mode of operation, various state information pertaining to wireless terminal  1  operations, and/or session information pertaining to wireless terminal  1 . 
   In some embodiments, the first and second type assignment messages are traffic channel assignment messages. In various embodiments, the first type assignment message can convey assignments for a plurality of traffic channel segments, e.g., up to three traffic channel segments, and second type assignments convey an assignment for a single traffic channel segment. 
   In various embodiments, the traffic channel structure information  1438  defines a recurring traffic channel structure and a mask value identifies potential traffic channel segments which may be assigned to a wireless terminal. For example, consider that the base station uses the traffic channel structure information of  FIGS. 7 and 8 . Referring to  FIG. 8A , if a wireless terminal is assigned a mask=111 or 001 the wireless terminal may be assigned uplink traffic channel segment with index number=3; however, if the wireless terminal is assigned a mask=010 or 100, the wireless terminal can not be assigned the uplink traffic channel segment with index number=3. Continuing with the example, if a wireless terminal is assigned a mask=111 or 001 or 010, the wireless terminal may be assigned the uplink traffic channel segment with index number=4; however if, the wireless terminal is assigned a mask=100, the wireless terminal can not be assigned the uplink traffic channel segment with index number=4. 
   In some embodiments, if the mask value assigned to a wireless terminal matches a first predetermined pattern, e.g., 111, any traffic channel segment from a set of traffic channel segments in the recurring traffic channel structure may be assigned to the wireless terminal and if the mask value matches a second predetermined pattern, e.g., 001, a first predetermined subset of said set of traffic channel segments in the recurring traffic channel structure may be assigned to the wireless terminal, and if the mask value matches a third predetermined pattern, e.g., 010, a second predetermined subset of said set of traffic channel segments in the recurring traffic channel structure may be assigned to the wireless terminal. In some such embodiments, the first predetermined subset and the second predetermined subset are partially overlapping. In some embodiments, if the mask value matches a fourth predetermined pattern, e.g., 100, a third predetermined subset of said set of traffic channel segments in the recurring traffic channel structure may be assigned to the wireless terminal, said third predetermined subset being partially overlapping with said first and second predetermined subsets. 
   In various embodiments, the mask identifier value is represented by a single information bit, said single bit distinguishing between two potential mask values which may be associated with the assignment. For example, consider that an exemplary first type assignment includes an assignment corresponding to uplink traffic channel segment with index=4 as indicated in  FIG. 8A , if the mask value identifier value is a first value, e.g., 0, that indicates mask 001, while if the mask identifier value is a second value, e.g., 1, that indicates mask 010. 
     FIG. 15  is a drawing of an exemplary wireless terminal  1500 , e.g., mobile node, implemented in accordance with various embodiments. Exemplary wireless terminal  1500  may be any of the wireless terminals of system  100  of  FIG. 1 . Exemplary wireless terminal  1500  includes a receiver module  1502 , a transmitter module  1504 , a processor  1506 , user I/O devices  1508 , and a memory  1510  coupled together via a bus  1512  over which the various elements interchange data and information. Memory  1510  includes routines  1518  and data/information  1520 . The processor  1506 , e.g., a CPU, executes routines  1518  and uses the data/information  1520  in memory  1510  to control the operation of the wireless terminal  1500  and implement methods. 
   Receiver module  1502 , e.g., an OFDM receiver, is coupled to receive antenna  1503  via which the wireless terminal receives downlink signals from base stations, e.g., from base station  1400 . Received downlink signals include timing/synchronization signals, control message signals conveying a base station assigned wireless terminal identifier and a corresponding mask value, first type assignment signals, second type assignment signals, and downlink traffic channel segment signals. Receiver module  1502  includes a decoder  1514  for decoding at least some of the received downlink signals. Transmission module  1504 , e.g., an OFDM transmitter, is coupled to transmit antenna  1505  via which the wireless terminal transmits uplink signals to base stations, e.g., to base station  1400 . Uplink signals include registration request signals, mode transition request signals, uplink dedicated control channel signals including requests for uplink traffic channel segment resources, and uplink traffic channel segment signals. Transmission module  1504  includes an encoder  1516  for encoding at least some of the uplink signals to be transmitted. In some embodiments, the same antenna is used for transmitter and receiver, e.g., in conjunction with a duplexer module. 
   User I/O devices  1508  include, e.g., microphone, camera, keyboard, touch-screen, keypad, switches, speaker, display, etc. User I/O devices  1508  allow a user of wireless terminal  1500  to input data/information, access output data/information, control at least some functions of wireless terminal  1500 , and/or control applications. 
   Routines  1518  include a communications routine  1522  and wireless terminal control routines  1524 . The communications routine  1522  implements various communications protocols used by the wireless terminal  1500 . Wireless terminal control routines  1524  include a control message processing module  1526 , a 1 st  type assignment processing module  1528 , a 2 nd  type assignment message processing module  1534 , an uplink traffic channel segment module  1536  and a downlink traffic channel segment module  1538 . 
   Control message processing module  1526  processes received control message information including a base station assigned wireless terminal identifier and a corresponding mask value, the mask value being represented by a first number of information bits. For example, the base station assigned wireless terminal identifier and mask value may be communicated via a state transition message and module  1524  processes this information storing the recovered information, e.g., for later use when processing assignment messages. Control message processing module  1526  also determines an operational mode based on the received mask value. For example in one exemplary embodiment, the mask value is conveyed by means of a two bit field conveying one of four potential mask patterns 111, 001, 010, and 100. If the value is 111, the wireless terminal is to be in a second mode of operation, while if the mask value is one of 001, 010, and 100, the wireless terminal is an a first mode of operation, with more resources being potentially available in the second mode of operation than in the first mode of operation, e.g., a larger number of traffic channel segments in the recurring traffic channel structure can be assigned to a wireless terminal in a second mode of On state operation as compared to a wireless terminal in a first mode of On state operation. In some embodiments, the second mode of operation is referred to a full tone format DCCH mode of operation and the first mode of operation is referred to a split tone format DCCH mode of operation. 
   1 st  type assignment message processing module  1528  processes assignment messages of a 1 st  type, said assignment messages of the 1 st  type including a wireless terminal identifier and a corresponding mask identifier value. In some such embodiments, the mask identifier value is represented by a second number of information bits, the second number of information bits being less than the first number of information bits. 1 st  type assignment message module  1528  identifies from a received 1 st  type assignment message whether or not a received assignment is directed to WT  1500 . 
   1 st  type assignment message processing module  1528  includes a 1 st  operational mode processing module  1530  and a 2 nd  operational mode processing module  1532 . 1 st  operational mode processing module  1530 , used when processing 1 st  type assignment messages when said wireless terminal in a first mode of operation, determines whether the received base station assigned wireless terminal identifier value currently associated with WT  1500  matches the wireless terminal identifier included in the assignment under consider from the 1 st  type assignment message being processed and whether the received mask identifier value of the assignment identifies the received mask value currently associated with WT  1500 . In one exemplary embodiment, when using 1 st  operational mode processing module, the received mask currently associated with WT  1500 , e.g., corresponding to mask value  1552  of the received control message is one of 001, 010 and 100. 
   2 nd  operational mode processing module  1532 , used when processing 1 st  type assignment messages when WT  1500  is in the second mode of operation, determines whether the received base station assigned wireless terminal identifier value currently corresponding to the wireless terminal matches the wireless terminal identifier in the received assignment message, and the determination by module  1532  as to whether of not the assignment under consideration is directed to WT  1500  does not require the use of the mask identifier value currently associated with WT  1500 , e.g., the mask value obtained from message  1548 . In one exemplary embodiment, when using 2 nd  operational mode processing module  1532 , the received mask currently associated with WT  1500 , e.g., corresponding to mask value  1552  of the received control message is 111, e.g., signifying that any traffic channel segment may be allocated to WT  1500 . 
   Second type assignment message processing module  1534  processes a second type assignment message including a wireless terminal identifier but not including a mask identifier value, and module  1534  identifies whether or not the second type assignment message is directed to WT  1500 . 
   Uplink traffic channel segment module  1536  is responsive to controlling the generation of uplink traffic channel segment signals and controlling the transmission of uplink traffic channel segment signals. Module  1536  is responsive to identified traffic channel segments  1570 ,  1574  which happen to be uplink traffic channel segments in the recurring traffic channel structure. Downlink traffic channel segment module  1538  is responsive to controlling the reception of downlink traffic channel segment signals and controlling the recovery of traffic channel segment signals. Module  1538  is responsive to identified traffic channel segments  1570 ,  1574  which happen to be downlink traffic channel segments in the recurring traffic channel structure. 
   Data/information  1520  includes stored traffic channel structure information  1540  and stored assignment/traffic channel segment mapping information  1546 . The stored traffic channel structure information  1540  includes segment  1 /mask association information  1542 , . . . , segment M/mask association information  1544 . Information  1540  corresponds to information  1438  in BS  1400 , while information  1546  corresponds to information  1440  in base station  1400 . For example some information from  FIGS. 7 and 8  is, in one embodiment, part of information  1540  and information  1546 . 
   Data/information  1520  also includes received control message information  1548  including a base station assigned wireless terminal identifier  1550  and a mask value  1552 , operational mode information,  1554 , base station attachment point identification information  1556 , a plurality of received 1 st  type assignment message information (received 1 st  type assignment message message 1 information  1558 , . . . , received 1 st  type assignment message message m information  1562 ), a plurality of 2 nd  type assignment message information (received 2 nd  type assignment message message 1 information  1564 , . . . , received 2 nd  type assignment message message n information  1568 ), information pertaining to identified traffic channel segments intended for WT  1500  (identified traffic channel segment  1  assigned to the WT  1570 , identified traffic channel segment X assigned to the WT  1574 ). 
   The received control message information  1548 , in some embodiments, is communicated via a state transition message. The information  1548  which is intended for WT  1500  is retained for use during subsequent assignment signaling processing operations. Operational mode  1554  includes information identifying the current state of WT  1500 , e.g., off, sleep, Hold, first mode of On state, second mode of On state. In some embodiments the first mode of On state is referred to as split tone format DCCH mode of operation and the second mode of ON state is referred to as a full tone format DCCH mode of operation. Base station attachment point identification information  1556  includes information identifying the current base station attachment point being used by WT  1500 , e.g., from among a plurality of base station attachment points in the system. Base station attachment point identification information  1556  includes, e.g., base station id, sector id, sector type identification, carrier identification, and/or tone block information. 
   Received 1 st  type assignment message message 1 information  1558  corresponds to a received 1 st  type message being processed and evaluated by module  1528 . Information  1558  includes, for a first assignment slot, a wireless terminal identifier  1560  and a corresponding mask identifier value, e.g. 1 bit,  1562 . Information  1558  for some messages includes a plurality of assignments, e.g., 2 nd  assignment information (WT identifier  1564  and corresponding mask identifier value  1566 ), and/or  3   rd  assignment information (WT identifier  1558  and corresponding mask identifier value  1560 ). 
   Received 2 nd  type assignment message message 1 information  1564 , which includes a wireless terminal identifier  1566  is processed by module  1534 . 
   Data/information  1520  also include data/information conveyed by identified segments assigned to WT  1500  (data/info conveyed by identified traffic channel segment  1   1572 , . . . , data/information conveyed by identified traffic channel segment X 1576 ). The identified segments ( 1570 ,  1574 ) may be identified from either of a 1 st  type assignment message by module  1528  or a second type assignment message by module  1534  and may correspond to either of an uplink traffic channel segment or a downlink traffic channel segment, e.g., in accordance with a predetermined mapping between assignment slots in the assignment messages and traffic channel segments in the recurring structure. 
   In some embodiments, the 1 st  and 2 nd  type assignment messages are traffic channel assignment messages. In one exemplary embodiment, the 1 st  type assignment message is referred to a regular assignment message and the 2 nd  type assignment message is referred to as a flash assignment. In some embodiments, a 1 st  type assignment message can convey multiple assignments, e.g., assignments for up to 3 different traffic channel segments and each of the traffic channel segments may be and sometimes is directed to a different wireless terminal. In some embodiments, the 2 nd  type assignment conveys an assignment for a single traffic channel segment. 
     FIG. 16 ,  FIG. 17  and  FIG. 18  illustrate exemplary state transition signaling, traffic channel assignment signaling and recurring channel structure in accordance with various embodiments.  FIGS. 16 ,  17  and  18  illustrate a simplified structure to illustrate features used in various embodiments.  FIG. 16  is a drawing  1600  illustrating exemplary state transition message signaling between an exemplary base station  1602  and a plurality of wireless terminal (WT A  1604 , WT B  1606 , WT C  1608 , WT D,  1610 , and WT E  1616 ). Base station  1602  may be any of the base stations of system  100  of  FIG. 1 . WTs ( 1604 ,  1606 ,  1608 ,  1610 ,  1612 ) may be any of the WTs of system  100  of  FIG. 1 . Base station  1602  transmits state transition message  1614  to WT A  1604  including a 5 bit WT ON identifier field=10001  1616  and a wtONMask field=00  1618 . WT A  1604  receives the message  1614  and determines that it has been assigned a WT ON ID=10001, a WT On MASK=001, and is to operate in a 1 st  ON mode of operation, e.g., split tone format DCCH mode. Base station  1602  transmits state transition message  1620  to WT B  1606  including a 5 bit WT ON identifier field=10001  1622  and a wtONMask field=01  1624 . WT B  1606  receives the message  1620  and determines that it has been assigned a WT ON ID=10001, a WT On MASK=010, and is to operate in a 1 st  ON mode of operation, e.g., split tone format DCCH mode. Base station  1602  transmits state transition message  1626  to WT C  1608  including a 5 bit WT ON identifier field=10001  1628  and a wtONMask field=10  1630 . WT C  1608  receives the message  1626  and determines that it has been assigned a WT ON ID=10001, a WT On MASK=100, and is to operate in a 1 st  ON mode of operation, e.g., split tone format DCCH mode. Base station  1602  transmits state transition message  1632  to WT D  1610  including a 5 bit WT ON identifier field=10010  1634  and a wtONMask field=11  1636 . WT D  1610  receives the message  1632  and determines that it has been assigned a WT ON ID=10010, a WT On MASK=111, and is to operate in a 2 nd  ON mode of operation, e.g., full tone format DCCH mode. Base station  1602  transmits state transition message  1638  to WT E  1612  including a 5 bit WT ON identifier field=11000  1640  and a wtONMask field=00  1642 . WT E  1612  receives the message  1638  and determines that it has been assigned a WT ON ID=11000, a WT On MASK=001, and is to operate in a 1 st  ON mode of operations, e.g., split tone format DCCH mode. 
     FIG. 17  is a drawing  1700  illustrating an exemplary recurring channel structure which may be used by the base station  1602  and wireless terminals ( 1604 ,  1606 ,  1608 ,  1610 ,  1612 ) of  FIG. 16 . Vertical axis  1702  represents frequency in a logical channel structure, while horizontal axis  1704  represents time. Information pertaining to the channel structure is stored and used by the base station and wireless terminals. In this exemplary channel structure each indexed traffic channel segment corresponds to an assignment slot in an assignment message by a predetermined relationship, and there are two types of assignment messages. The first type of assignment message, e.g., a regular assignment message, has slots for two assignments, while the second type of assignment message, e.g., a flash type assignment message, conveys an assignment for a single traffic channel segment. In some embodiments, the second type assignment is transmitted at a higher power level than the first type of assignment. 
   This exemplary embodiment includes 10 indexed traffic channel segments (traffic channel segment  0   1718 , traffic channel segment  1   1720 , traffic channel segment  2   1722 , traffic channel segment  3   1724 , traffic channel segment  4   1726 , traffic channel segment  5   1728 , traffic channel segment  6   1730 , traffic channel segment  7   1732 , traffic channel segment  8   1734 , traffic channel segment  9   1736 ), four type 1 assignment messages (type 1 assignment message  1   1708 , type 1 assignment message  2   1710 , type 1 assignment message  3   1714 , type 1 assignment message  4   1716 ), and two type 2 assignment messages (type 2 assignment message  1   1706 , type 2 assignment message  2   1712 ). 
   Type 2 assignment message  1   1706  conveys the assignment for traffic channel segment  0   1718 . Traffic channel segment  0  can be assigned to a wireless terminal in the second mode of operation or a wireless terminal in the first mode of operation with an assigned WT ON Mask=001. 
   Type 1 assignment message  1   1708  conveys the assignment for traffic channel segment  1   1720  and the assignment for traffic channel segment  2   1722 . Traffic channel segment  1   1720  can be assigned to a wireless terminal in the second mode of operation or a wireless terminal in the first mode of operation with an assigned WT ON Mask=001 or 010. Traffic channel segment  2   1722  can be assigned to a wireless terminal in the second mode of operation or a wireless terminal in the first mode of operation with an assigned WT ON Mask=001 or 100. 
   Type 1 assignment message  2   1710  conveys the assignment for traffic channel segment  3   1724  and the assignment for traffic channel segment  4   1726 . Traffic channel segment  3   1724  can be assigned to a wireless terminal in the second mode of operation or a wireless terminal in the first mode of operation with an assigned WT ON Mask=010 or 100. Traffic channel segment  4   1726  can be assigned to a wireless terminal in the second mode of operation or a wireless terminal in the first mode of operation with an assigned WT ON Mask=010 or 001. 
   Type 2 assignment message  2   1712  conveys the assignment for traffic channel segment  5   1728 . Traffic channel segment  5  can be assigned to a wireless terminal in the second mode of operation or a wireless terminal in the first mode of operation with an assigned WT ON Mask=010. 
   Type 1 assignment message  3   1714  conveys the assignment for traffic channel segment  6   1730  and the assignment for traffic channel segment  7   1732 . Traffic channel segment  6   1730  can be assigned to a wireless terminal in the second mode of operation or a wireless terminal in the first mode of operation with an assigned WT ON Mask=001 or 010. Traffic channel segment  7   1732  can be assigned to a wireless terminal in the second mode of operation or a wireless terminal in the first mode of operation with an assigned WT ON Mask=100 or 010. 
   Type 1 assignment message  4   1716  conveys the assignment for traffic channel segment  8   1734  and the assignment for traffic channel segment  9   1736 . Traffic channel segment  8   1734  can be assigned to a wireless terminal in the second mode of operation or a wireless terminal in the first mode of operation with an assigned WT ON Mask=001 or 010. Traffic channel segment  9   1736  can be assigned to a wireless terminal in the second mode of operation or a wireless terminal in the first mode of operation with an assigned WT ON Mask=001 or 100. 
     FIG. 18  is a drawing  1800  illustrating exemplary assignments for each of the exemplary traffic channel segments of  FIG. 17 .  FIG. 18  illustrates information conveyed in exemplary assignment messages in view of the configuration established via the state transition message signaling of  FIG. 16  and the structure of  FIG. 17 . The assignments are determined by the base station and communicated to the wireless terminals. A wireless terminal receives and process assignment signals and determines whether or not a particular assignment is directed to itself. 
   Base station  1602  has decided to assign traffic channel segment  0  to WT A  1604  as indicated by block  1818  and includes a 5 bit WT identifier=10001 in the corresponding assignment message as indicated by block  1806 . Base station  1602  has decided to assign traffic channel segment  1  to WT B  1606  as indicated by block  1820  and includes a 5 bit WT identifier=10001 and a 1 bit WT mask identifier=1 in the corresponding assignment message as indicated by block  1808 . Base station  1602  has decided to assign traffic channel segment  2  to WT D  1610  as indicated by block  1822  and includes a 5 bit WT identifier=10010 and a 1 bit WT mask identifier field with a don&#39;t care condition, either a 0 or a 1 in the WT mask identifier field, in the corresponding assignment message as indicated by block  1808 . 
   Base station  1602  has decided to assign traffic channel segment  3  to WT C  1608  as indicated by block  1824  and includes a 5 bit WT identifier=10001 and a 1 bit WT mask identifier=1 in the corresponding assignment message as indicated by block  1810 . Base station  1602  has decided to assign traffic channel segment  4  to WT D  1610  as indicated by block  1826  and includes a 5 bit WT identifier=10010 and a 1 bit WT mask identifier field with a don&#39;t care condition in the corresponding assignment message as indicated by block  1810 . 
   Base station  1602  has decided to assign traffic channel segment  5  to WT D  1610  as indicated by block  1828  and includes a 5 bit WT identifier=10010 in the corresponding assignment message as indicated by block  1828 . Base station  1602  has decided to assign traffic channel segment  6  to WT B  1606  as indicated by block  1830  and includes a 5 bit WT identifier=10001 and a 1 bit WT mask identifier=1 in the corresponding assignment message as indicated by block  1814 . Base station  1602  has decided to assign traffic channel segment  7  to WT C  1608  as indicated by block  1832  and includes a 5 bit WT identifier=10001 and a 1 bit WT mask identifier=0 in the corresponding assignment message as indicated by block  1814 . 
   Base station  1602  has decided to assign traffic channel segment  8  to WT A  1604  as indicated by block  1834  and includes a 5 bit WT identifier=10001 and a 1 bit WT mask identifier=0 in the corresponding assignment message as indicated by block  1816 . Base station  1602  has decided to assign traffic channel segment  9  to WT E  1612  as indicated by block  1836  and includes a 5 bit WT identifier=11000 and a 1 bit WT identifier mask=0 in the corresponding assignment message as indicated by block  1816 . 
   Note that in this exemplary embodiment, the assignment segments have a predetermined mapping to the traffic channel segments in accordance with the channel structure; therefore, the assignment messages, in various embodiments, need not and in various embodiments do not include a field identifying the index of the segment to which the assignment corresponds. The wireless terminals can determine by the position of the assignment, e.g., frequency, time in the recurring timing structure, and/or assignment slot position, the particular traffic channel segment to which an assignment corresponds. 
   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 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, signal processing, message generation 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). 
   While described in the context of an OFDM system, at least some of the methods and apparatus, 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 described above will be apparent to those skilled in the art in view of the above description. Such variations are to be considered within 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.