Method for sharing hybrid resources in a wireless independent network, a station for the method, and a data format for the method and the station

id="REI-00001" date="20120515"

CROSS-REFERENCE TO RELATED APPLICATIONS

id="REI-00001"

0001Notice: More than one reissue application has been filed for a reissue of U.S. Pat. No. 7,453,846. The reissue applications are Reissue application Ser. No. 12/718,087, which is for a reissue of U.S. Pat. No. 7,453,846, and Continuation Reissue application Ser. Nos. 13/170,786 (the present continuation reissue application), 13/171,092, 13/171,255, and 13/171,369, all of which are continuation reissue applications of Reissue application Ser. No. 12/718,087, and all of which are for a reissue of U.S. Pat. No. 7,453,846. This reissue application is a continuation reissue application of Reissue application Ser. No. 12/718,087 filed on Mar. 5, 2010, now U.S. Pat. No. Re. 42,850, which is for a reissue of U.S. Pat. No. 7,453,846, which issued on Nov. 18, 2008, from application Ser. No. 10/314,295 filed on Dec. 9, 2002, which claims the benefit of Korean Application No. 2001-78664 filed on Dec. 12, 2001.

BACKGROUND OF THE INVENTION

00021. Field of the Invention

0003The present invention relates to a wireless independent network based on carrier sense multiplexing access (CSMA)/collision avoidance (CA). More particularly, the present invention relates to a method for sharing hybrid resources in a wireless independent network, a station for the method, and a data format for the method and the station.

00042. Description of the Related Art

0005Wireless independent networks connect wireless stations without the use of wires in a predetermined area regardless of connections to base networks. For example, home networks connecting information regarding home electronics without the use of wires is a type of wireless independent network. Services in a wireless independent network may generally be classified into a real-time AudioVideo (AV) streaming service or a non-real-time AV streaming service.

0006An environment of such a wireless independent network may be characterized as follows. First, since network subscribers' interests concentrate on a real-time AV streaming service in one independent network, it is rare for a large number of real-time AV services to coexist in one independent network. Second, a small number of real-time AV streaming services and a large number of non-real-time AV streaming services can coexist in one independent network. Third, the real-time AV streaming service uses a station that is the subject thereof and limited holding time exists in the service.

0007In the above-described wireless independent network environment, wireless stations (STAs) typically share wireless communications resources. Here, a conventional resource-sharing method may generally be classified into a distributed coordination method or a centralized control method.

0008The distributed coordination method uses a mechanism for minimizing possible message collisions that occur when stations attempt to use a data channel simultaneously. This mechanism is the IEEE 802.11a distributed coordination function (DCF) based on CSMA/CA. In a distributed coordination method using a DCF, random backoff numbers are created to minimize competition-based collisions, the backoff numbers are reduced by stages when a channel is idle for at least a predetermined period of time (in the case of IEEE 802.11, this is referred to as DCF Interframe Space (DIFS)), and data is transmitted when the backoff number becomes “0”. A conventional distributed coordination method for grading priorities of the occupation of resources according to a specific type of data includes a Point Coordination Function (PCF) Interframe Space (PIFS) system and a Short lnterframe Space (SIFS). Priorities of these systems are in the relationship DIFS>PIFS>SIFS, and a station using SIFS has priority over a station using DIFS. However, since a DCF system works on a probabilistic base, it is still possible for stations to collide.

0009In the centralized control method, one control station controls resources shared in a wireless independent network in a bundle. Thus, wireless stations share wireless resources according to the instructions of the control station. The centralized control method may be subdivided into a direct mode and an indirect mode. In the direct mode, a control station controls the time slots for transmission and reception among wireless stations so that the wireless stations directly communicate with one another. The HiperLAN/2 standard is a representative example of the direct mode. In the indirect mode, transmission data of all stations is transmitted to the control station so that the wireless stations indirectly communicate with one another through the control station. This indirect mode is based on the Bluetooth standard.

0010Accordingly, in the above-described distributed coordination method, a specific control station is not required, and a mesh network can be constituted, and a station may easily subscribe to and withdraw from the mesh network. However, the distributed coordination method uses resources ineffectively and cannot support the real-time AV streaming service. In addition, the centralized control method in the indirect mode cannot support the real-time AV streaming service due to the forwarding of packets, which concentrates loading on the control station, and requires the selection of a substitute node when the control station withdraws from the subscribed network. Although the centralized control method in the direct mode uses resources effectively, supports the real-time AV streaming service, and constitutes the mesh network, loading is concentrated on the control station, thus requiring the selection of a substitute node when the control station withdraws from the subscribed network.

0011The aforementioned conventional resource-sharing methods have many problems since they have been developed based on non-real-time services, or due to inflexible structure of networks.

SUMMARY OF THE INVENTION

0012In an effort to solve the above-described problems, it is a first feature of an embodiment of the present invention to provide a method for sharing hybrid resources in a wireless independent network that can have the advantages of conventional resource-sharing methods by more efficiently analyzing the environment of the wireless independent network so that wireless resources are shared adaptive to the environment, thereby efficiently supporting real-time services as well as non-real-time services among the wireless stations.

0013It is a second feature of an embodiment of the present invention to provide stations performing the hybrid resources sharing method.

0014It is a third feature of an embodiment of the present invention to provide formats of data transmitted among the stations.

0015Accordingly, a method for sharing wireless hybrid resources among stations in a wireless independent network preferably includes analyzing a received data stream and obtaining network control for optimally transferring that data. An analysis is performed to determine whether currently transmitted data is related to a real-time service when the sharing of the wireless hybrid resources is controlled by a distributed coordination method. A sharing control authority is requested and received by the distributed coordination method, and the sharing of the wireless hybrid resources is controlled by a centralized control method in a direct mode until the real-time service ends if it is determined that the currently transmitted data is related to the real-time service. The sharing control authority corresponds to an authority which controls the sharing of the wireless hybrid resources. If it is determined that the currently transmitted data is not related to the real-time service, the sharing of the wireless hybrid resources may be controlled by the distributed coordination method.

0016Obtaining network control when the currently transmitted data is related to the real-time service preferably includes requesting the sharing control authority by the distributed coordination method if it is determined that the currently transmitted data is related to the real-time service; determining whether the request for the sharing control authority is rejected; controlling the sharing of the wireless hybrid resources with a request for periodic polling, if it is determined that the request is rejected; and then determining whether the sharing of the wireless hybrid resources does not need to be controlled during the real-time service. If it is determined that the sharing of the wireless hybrid resources does not need to be controlled during the real-time service, control is transferred to the aforementioned requesting step. If it is determined the sharing of the wireless hybrid resources still needs to be controlled during the real-time service, control is returned to the step for requesting for periodic polling.

0017If it is determined that the request for the sharing control authority is not rejected, the method preferably additionally includes receiving the sharing control authority and controlling the sharing of the wireless hybrid resources by the centralized control method in the direct mode; determining whether the real-time service ends and returning to the receiving step if it is determined that the real-time service does not end; and returning the sharing control authority if it is determined that the real-time service ends. In the foregoing additional steps, the sharing of the wireless hybrid resources is preferably controlled by the distributed coordination method.

0018A preferred embodiment of a station for performing the wireless hybrid resources sharing method according to the present invention preferably includes a transmission data checking unit and a first controller. The preferred embodiment of the station may further include a second controller. The transmission data checking unit checks whether the currently transmitted data is related to the real-time service and generates a control signal in response to the check result. In response to the control signal, the first controller requests and receives the sharing control authority by the distributed coordination method and controls the sharing of the wireless hybrid resources by the centralized control method in the direct mode until the real-time service ends. Alternately, a second controller may control the sharing of the wireless hybrid resources by the distributed coordination method in response to the control signal.

0019The first controller preferably further includes a request message broadcaster, which broadcasts a control authority requesting message requesting the sharing control authority by the distributed coordination method in response to the control signal and an enable signal; a request rejecting message receiver, which receives a control authority request rejecting message rejecting the request for the sharing control authority and outputs a disable signal in response to the received result; a polling requesting unit, which requests periodic polling in response to the disable signal and the enable signal; a releasing message receiver, which receives a control authority releasing message in response to the control signal and outputs the enable signal in response to the received result; a shared resource controller, which receives the sharing control authority in response to the disable signal and controls the sharing of the wireless hybrid resources by the centralized control method in the direct mode and transmits the sharing control authority releasing message to another station and returns the sharing control authority in response to an ending signal; and a service checking unit, which checks whether the real-time service ends and outputs the checked result as the ending signal. Preferably, a second controller controls the sharing of the wireless hybrid resources by the distributed coordination method in response to the ending signal.

0020To operate the foregoing preferred station using the foregoing preferred method for sharing wireless hybrid resources, a data format preferably includes a control authority requesting message, a control Authority releasing message, and a plurality of transmission frames located therebetween. The control authority requesting message requests the sharing control authority by the distributed coordination method. The control authority releasing message releases the sharing control authority. The plurality of transmission frames are spaced apart from the control authority requesting message and the control authority releasing message, by a PIFS, are also spaced apart from each other by one PIFS, and may have variable lengths.

0021Each one of the plurality of transmission frames preferably further includes a downlink section in which the real-time service-related data is transmitted to another station and which may have a variable length; a polling section in which the other stations related to the real-time service is polled and which has a variable length; and a distribution control section in which non-real-time service-related data is transmitted to another station and which may have a variable length. The downlink section is preferably spaced apart from the polling section by a PIFS. The polling section is preferably spaced apart from the distribution control section by a DIFS. The downlink section preferably includes a plurality of packets which are spaced apart from each other by a PIFS.

0022In the event that a share request rejection message is received in the station, a sharing control authority message may also be received. In such a case, the shared resource controller is preferably idle for a PIFS period, thereby necessitating the inclusion of a PIFS time period between the time of the request for sharing control authority and the receipt of the sharing control authority. Additionally, in the event a sharing rejection message is transmitted by the sharing controller, preferably a SIFS time period is included in the format between the time of transmission of the request and the time of receipt of the rejection message.

BRIEF DESCRIPTION OF THE DRAWINGS

0023The above and other features and advantages of the present invention will become readily apparent to those of ordinary skill in the art by describing in detail preferred embodiments thereof with reference to the attached drawings in which:

0024<figref idref="DRAWINGS">FIG. 1</figref> illustrates a flowchart of a method for sharing hybrid resources in a wireless independent network according to the present invention;

0025<figref idref="DRAWINGS">FIG. 2</figref> illustrates a flowchart of a preferred embodiment of step <b>12</b> shown in <figref idref="DRAWINGS">FIG. 1</figref> according to the present invention;

0026<figref idref="DRAWINGS">FIG. 3</figref> illustrates a block diagram of a station, according to the present invention, performing the hybrid resources sharing method shown in <figref idref="DRAWINGS">FIG. 1</figref>;

0027<figref idref="DRAWINGS">FIG. 4</figref> illustrates a block diagram of a preferred embodiment of a first controller shown in <figref idref="DRAWINGS">FIG. 3</figref> according to the present invention;

0028<figref idref="DRAWINGS">FIGS. 5(a)</figref>, (b), and (c) illustrate data formats for the above-described hybrid resources sharing method and the station according to the present invention;

0029<figref idref="DRAWINGS">FIG. 6</figref> illustrates an exploded view of a preferred embodiment of a downlink section shown in <figref idref="DRAWINGS">FIG. 5(c)</figref>; and

0030<figref idref="DRAWINGS">FIGS. 7(a)</figref> and (b) illustrate how the sharing control authority is obtained and how a message rejecting the request for the sharing control authority is received from a control station, respectively, after a message requesting a sharing control authority is broadcasted.

DETAILED DESCRIPTION OF THE INVENTION

0031Korean Patent Application No. 2001-78664, filed Dec. 12, 2001, and entitled: “Method for Sharing Hybrid Resources in Wireless Independent Network, Station for the Method, and Data Format for the Method and the Station,” is incorporated by reference herein in its entirety.

0032Hereinafter, a method for sharing hybrid resources in a wireless independent network according to the present invention will be described with reference to the attached drawings. In the drawings, like reference numerals refer to like elements throughout.

0033<figref idref="DRAWINGS">FIG. 1</figref> illustrates a flowchart of a preferred method for sharing hybrid resources in a wireless independent network according to the present invention. Selection of either a centralized control method in a direct mode or a distributed coordination method is preferably dependent on whether real-time service-related data is transmitted. In step <b>10</b>, a determination is made as to whether currently transmitted data is related to a real-time service when the sharing of the wireless resources is controlled based on the above-described distributed coordination method. For example, it may be determined that a real-time AV streaming service is being generated, i.e., the real-time AV streaming service is provided via a wireless independent network. If the currently transmitted data is not related to the real-time service, the distributed coordination method is retained in step <b>14</b>.

0034If, however, the currently transmitted data is related to the real-time service when the sharing of the wireless resources is controlled by the distributed coordination method, in step <b>12</b>, a station which is the subject of the real-time service (hereinafter referred to as “subject station”) requests a sharing control authority using the distributed coordination method. After the request is admitted sharing control authority is granted to the subject station, and wireless resources are shared under control of the subject station preferably using the centralized control method in a direct mode for the duration of the transmission of the corresponding real-time service. At the completion of the real-time service transmission the subject station restores the sharing of the wireless resources to the distributed coordination method.

0035<figref idref="DRAWINGS">FIG. 2</figref> illustrates a flowchart of a preferred embodiment of step <b>12</b> shown in <figref idref="DRAWINGS">FIG. 1</figref> according to the present invention. Step <b>12</b> preferably includes steps <b>20</b> and <b>22</b> for requesting the sharing control authority, steps <b>24</b> through <b>28</b> for controlling the sharing of wireless resources with a request for periodic polling when the requested sharing control authority is rejected, and steps <b>30</b> through <b>34</b> for controlling the sharing of the wireless resources by the centralized control method in the direct mode until the real-time service ends when the requested sharing control authority is admitted.

0036After it is determined that the currently transmitted data is related to the real-time service, in step <b>20</b> the subject station requests the sharing control authority using the distributed coordination method, e.g., a DCF system. In step <b>22</b>, the subject station determines whether the request for sharing control authority has been rejected. In other words, the subject station determines whether a station currently having a sharing control authority (hereinafter referred to as a “control station”) exists by testing for the existence of a “rejection message” from that control station.

0037If it is determined that the request for the sharing control authority is rejected, in step <b>24</b> the sharing of the wireless resources is controlled while the subject station requests the control station for periodic polling. For example, if the control station exists, the subject station cannot be granted the sharing control authority, and the control station maintains the sharing control of the wireless resources and a corresponding real-time AV streaming service-related communication is implemented using the existing method.

0038In step <b>26</b> the subject station determines whether the real-time service is still being transmitted, i.e., still in progress. If it is determined that the real-time service is still being transmitted, in step <b>28</b> the subject station determines whether the sharing of the wireless resources needs to be controlled. In other words, if it has been determined that the real-time service is in process, the subject station monitors whether a control authority releasing message has been received from the control station.

0039If it is determined through the periodic polling that the sharing of the wireless resources does not need to be controlled by the control station for performing the corresponding real-time service-related communication, the process returns to step <b>20</b>. In other words, when the subject station does not need to be controlled by the control station any more, it requests the acquisition of the sharing control authority by the distributed coordination method again. However, if it is determined that the subject stations still needs to be controlled by the control station to share the wireless resources when the real-time service is in progress, the process returns to step <b>24</b>.

0040Alternatively, if it is determined that the request for the sharing control authority has not been rejected, in step <b>30</b> the subject station is granted (i.e., assumes or seizes) the sharing control authority and preferably controls the sharing of the wireless resources by the centralized control method in the direct mode. In step <b>32</b>, it is determined whether the real-time service has ended. If it is determined that the real-time service has not ended, the process repeats step <b>30</b>, such that the subject station retains the sharing control authority. However, if it is determined that the real-time service has ended, in step <b>34</b> the subject station broadcasts a new control authority releasing message to the other stations to return the sharing control authority to the network. When it is determined that the real-time service is not in progress in step <b>26</b> or after step <b>34</b>, the subject station changes the sharing controls back to the distributed coordination method.

0041A preferred embodiment according to the present invention, showing the structure and operation of stations in an independent network performing the previously described hybrid resources sharing method will be described with reference to <figref idref="DRAWINGS">FIGS. 3 and 4</figref>.

0042<figref idref="DRAWINGS">FIG. 3</figref> illustrates a block diagram of a station for performing the hybrid resources sharing method shown in <figref idref="DRAWINGS">FIG. 1</figref>, according to an embodiment of the present invention. The station preferably includes a transmission data checking unit <b>50</b>, and a first and a second controller <b>52</b> and <b>54</b>, respectively. For a better understanding of the present invention, the structure and operation of the station shown in <figref idref="DRAWINGS">FIG. 3</figref> will be described assuming that the station is a subject station.

0043The transmission data checking unit <b>50</b> checks whether currently transmitted data input via an input port IN<b>1</b> is related to a real-time service and outputs a control signal to first and second controllers <b>52</b> and <b>54</b>, respectively. First and second controllers <b>52</b> and <b>54</b> generate output control and data signals in response to the check result.

0044If first controller <b>52</b> is granted a sharing control authority in response to the control signal input from the transmission data checking unit <b>50</b>, the sharing of wireless resources on a central controls system in a direct mode is controlled by first controller <b>52</b>using a centralized control method in a direct mode until the real-time service ends. To perform this control function, if it is perceived through the control signal that data input via the input port IN<b>1</b> is transmission data for the real-time service, the first controller <b>52</b> outputs a signal requesting the sharing control authority to the other stations via an output port OUT<b>1</b> and checks whether a message rejecting the request for the sharing control authority is received from another station, e.g., a control station (not shown), via the input port IN<b>1</b>. If the first controller <b>52</b> is granted the sharing control authority (i.e., not rejected) data input through the input port IN<b>1</b> via the transmission data checking unit <b>50</b> is transmitted to a corresponding station (not shown) via the output port OUT<b>1</b>.

0045The second controller <b>54</b> controls the sharing of the wireless resources by the distributed coordination method in response to the control signal input from the transmission data checking unit <b>50</b>. Here, the second controller <b>54</b> preferably receives data from another station via an input port IN<b>3</b> and outputs the data input through the input port IN<b>1</b> via the transmission data checking unit <b>50</b> to another station via an output port OUT<b>2</b>. Here, the second controller <b>54</b> may control the sharing of the wireless resources by the distributed coordination method in response to an ending signal generated when the real-time services ends in the first controller <b>52</b>.

0046<figref idref="DRAWINGS">FIG. 4</figref> illustrates a block diagram of a preferred embodiment of the first controller <b>52</b> shown in <figref idref="DRAWINGS">FIG. 3</figref>. The first controller <b>52</b> preferably includes a request message broadcaster <b>70</b>, a request rejecting message receiver <b>72</b>, a polling requesting unit <b>74</b>, a releasing message receiver <b>76</b>, a shared resource controller <b>78</b>, and a service checking unit <b>80</b>.

0047To perform step <b>20</b>, in response to the control signal from transmission data checking unit <b>50</b> via an input port IN<b>4</b> (indicating that received data is related to a real-time service,)service), the request message broadcaster <b>70</b> transmits a message requesting control authority to the other stations via an output port OUT<b>3</b> using the distributed coordination method. The request message is additionally gated using an enable signal input from the releasing message receiver <b>76</b>. If one of the other stations has sharing control authority (i.e., is processing data), that “control station” transmits a rejection message to the subject station. When the control station has completed its data processing activity, it transmits a sharing control authority releasing message using the distributed coordination method. If, however, there is no currentactive control station, no rejection message will be received.

0048To perform step <b>22</b>, the request rejecting message receiver <b>72</b> receives any message rejecting the request for the sharing control authority via an input port IN<b>5</b> and outputs the received message as a disable signal to the polling requesting unit <b>74</b> and the shared resource controller <b>78</b>. In response to the disable signal from the request rejecting message receiver <b>72</b> and the enable signal input from the releasing message receiver <b>76</b>, the polling requesting unit <b>74</b>, which performs step <b>24</b>, requests the periodic polling from the control station via an output port OUT<b>4</b>. In other words, the polling requesting unit <b>74</b> requests the periodic polling of the control station whenever a rejection message is received and the sharing control authority releasing message has not yet been received.

0049To perform steps <b>26</b> and <b>28</b>, in response to the control signal input from the transmission data checking unit <b>50</b> via the input port IN<b>4</b> (indicating the real-time service) the releasing message receiver <b>76</b> monitors the control station for the sharing control authority releasing message via an input port IN<b>6</b>. When the sharing control authority releasing message is received, releasing message receiver <b>76</b> outputs an enable signal to the request message broadcaster <b>70</b> and the polling requesting unit <b>74</b>. The releasing message receiver <b>76</b> may generate an enable signal having a first logic level if the sharing control authority releasing message is received from the control station and an enable signal having a second logic level if the control authority releasing message is not received from the control station.

0050For the case where no rejection message is received, the shared resource controller <b>78</b>, which performs steps <b>30</b> and <b>34</b>, assumes the sharing control authority in response to the disable signal input from the request rejecting message receiver <b>72</b> and thus controls the sharing of the wireless resources using the centralized control method in the direct mode. Here, the shared resource controller <b>78</b> may receive data from another station via an input port IN<b>7</b> or may output data for the real-time service to another station via an output port OUT<b>5</b>. Also, in step <b>34</b>, the shared resource controller <b>78</b> preferably transmits the sharing control authority releasing message to another station via the output port OUT<b>5</b> to return the sharing control authority in response to the ending signal input from the service checking unit and sharing control authority<b>80</b>. Although it is not shown as a step in <figref idref="DRAWINGS">FIG. 2</figref>, during the time that the subject station has the control authority, the shared resource controller <b>78</b> preferably transmits the sharing control rejection messages upon being queried by other stations.

0051The service checking unit <b>80</b>, which performs step <b>32</b>, checks whether the real-time service has ended and outputs the check result as the ending signal to the shared resource controller <b>78</b> and to the second controller <b>54</b> via the output port OUT<b>6</b>. Here, the second controller <b>54</b> controls the sharing of the wireless resources by the distributed coordination method in response to the ending signal input from the service checking unit <b>80</b>.

0052Hereinafter, a data format for the hybrid resource-sharing method and the station according to the present invention will be described with reference to the attached drawings.

0053<figref idref="DRAWINGS">FIGS. 5(a)</figref>, (b), and (c) illustrate a timing diagram of a streaming messaging signal having a plurality of partitioning sections according to a preferred data format for the above-described resource-sharing method and station according to the present invention. <figref idref="DRAWINGS">FIG. 5(a)</figref> shows sections of the complete data stream and <figref idref="DRAWINGS">FIGS. 5(b) and 5(c)</figref> show exploded views of the partitions of a transmission frame.

0054According to the present invention, step <b>10</b> of the preferred method shown in <figref idref="DRAWINGS">FIG. 1</figref> is performed byduring a distributed coordination method during section <b>90</b> shown in <figref idref="DRAWINGS">FIG. 5(a)</figref>. Here, if it is determined that currently transmitted data is related to the real-time service, step <b>12</b> is performed during an adaptive control method section <b>92</b> shown in <figref idref="DRAWINGS">FIG. 5(a)</figref>. For this, the subject station obtains the sharing control authority at a starting point <b>97</b> of the adaptive control systemmethod section <b>92</b>. The length <b>96</b> of the adaptive control systemmethod section <b>92</b> may vary. When the real-time service ends during step <b>12</b>, the subject station returns the sharing control authority at an ending point <b>98</b> of the adaptive control systemmethod section <b>92</b>.

0055As shown in <figref idref="DRAWINGS">FIG. 5(b)</figref>, the adaptive control systemmethod section <b>92</b> shown in <figref idref="DRAWINGS">FIG. 5(a)</figref> preferably includes a control authority requesting message <b>100</b>, a series of first through n-th transmission frames <b>102</b>, <b>104</b>, . . . and <b>106</b>, and a control authority releasing message <b>108</b>. The first transmission frame <b>102</b> is spaced apart from the control authority requesting message <b>100</b> by a Point Coordination Function (PCF) Interframe Space (PIFS) <b>120</b> and the n-th transmission frame <b>106</b> is spaced apart from the control authority releasing message <b>108</b> by a PIFS <b>126</b>. The first through n-th transmission frames <b>102</b>, <b>104</b>, . . . , and <b>106</b> are spaced apart from each other by a PIFS <b>122</b> to have priority of the occupation of the resources over DCF-based wireless stations. Here, the first through n-th transmission frames <b>102</b>, <b>104</b>, . . . and <b>106</b> have lengths <b>124</b>, respectively, which may vary depending on characteristics of a corresponding AV streaming service.

0056As shown in <figref idref="DRAWINGS">FIG. 5(c)</figref>, each one of the first through n-th transmission frames <b>102</b>, <b>104</b>, . . . and <b>106</b> preferably includes a downlink section <b>140</b>, a polling section <b>142</b>, and a distribution control section <b>144</b>. In the downlink section <b>140</b>, real-time service-related transmission data is transmitted to another station and the downlink section <b>140</b> has a variable length <b>160</b>. In the polling section <b>142</b>, which has a variable length <b>162</b>, other real-time service-related stations may be polled, and a multiplex polling system may be used for improved performance. In the polling section <b>142</b>, a packet is forwarded from the subject station to the control station or another station.

0057In the distribution control section <b>144</b>, which has a variable length <b>164</b>, non-real-time service-related transmission data is preferably transmitted to another station using a DCF system. If an additional real-time AV streaming service is generated, the message requesting the periodic polling may be transmitted to the control station. Here, the downlink section <b>140</b> is spaced apart from the polling section <b>142</b> by a PIFS <b>170</b>, and the polling section <b>142</b> is spaced apart from the distribution control section <b>144</b> by a DIFS <b>172</b>.

0058<figref idref="DRAWINGS">FIG. 6</figref> illustrates an exploded view of a preferred embodiment of the downlink section <b>140</b> of <figref idref="DRAWINGS">FIG. 5(c)</figref> according to the present invention, which preferably includes a plurality of packets <b>182</b>, <b>184</b>, . . . and <b>186</b>. Referring to <figref idref="DRAWINGS">FIG. 6</figref>, the plurality of packets <b>182</b>, <b>184</b>, . . . and <b>186</b> are spaced apart from each other by a PIFS <b>180</b> to maintain the sharing control authority for the downlink section <b>140</b>.

0059<figref idref="DRAWINGS">FIGS. 7(a)</figref> and (b) illustrate views explaining how the sharing control authority is obtained and how the message rejecting the request for the sharing control authority is received from the control station, respectively, after the message requesting the sharing control authority has been transmitted. In <figref idref="DRAWINGS">FIG. 7(a)</figref>, there is no currentactive control station, while in <figref idref="DRAWINGS">FIG. 7(b)</figref>, there is a currentan active control station.

0060As shown in <figref idref="DRAWINGS">FIG. 7(a)</figref>, the request message broadcaster <b>70</b> transmits a control authority requesting message <b>192</b> via the output port OUT<b>3</b>. After the shared resource controller <b>78</b> shown in <figref idref="DRAWINGS">FIG. 4</figref> is idle for a PIFS <b>190</b>, sharing control authority is assumed in section <b>194</b>.

0061For the case where an active control station exists, as shown in <figref idref="DRAWINGS">FIG. 7(b)</figref>, the request message broadcaster <b>70</b> broadcasts a control authority requesting message <b>202</b>. Then after a SIFS <b>200</b> elapses, the request rejecting message receiver <b>72</b> shown in <figref idref="DRAWINGS">FIG. 4</figref> receives a control authority request rejecting message <b>204</b> from the active control station. After a variable time duration <b>206</b> during which the active control station completes its control task, a sharing control authority releasing message <b>208</b> is transmitted by the active control station, thereby releasing network sharing control authority.

0062At this time the request message broadcaster <b>70</b> again transmits a control authority requesting message <b>192</b> as in <figref idref="DRAWINGS">FIG. 7(a)</figref>, and after the shared resource controller <b>78</b> is idle for a PIFS <b>190</b>, sharing control authority is assumed in section <b>194</b>. In an alternate embodiment, the active control station may transmit the sharing control authority releasing message <b>208</b> directly to the requesting station, thereby allowing the requesting station to immediately assume sharing control authority in section <b>194</b>, and thus avoiding the loss of time periods <b>190</b> and <b>192</b>.

0063As described above, in a preferred method for sharing hybrid resources in a wireless independent network, a station for the method, and a data format for the method and the station, non-real-time service-related data packets are transmitted/received using a distributed coordination method and real-time service-related data packets are transmitted/received using a centralized control method in a direct mode. In other words, hybrid data is transmitted and received in a wireless independent network. Thus, an efficiency of using resources is maximized, a real-time service of the resources is supported, and a mesh network may be constituted. Further, loading may be prevented from concentrating in a control station and the control station is not fixed. As a result, a station can freely subscribe/withdraw to/from a subscribed network.

0064Preferred embodiments of the present invention have been disclosed herein and, although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. Accordingly, it will be understood by those of ordinary skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.