MXPA06008743A - A system and method for an ultra wide-band medium access control distributed reservation protocol - Google Patents

Abstract

A system (300), apparatus (301), and method are provided for decentralized medium access control comprising an enhanced protocol for UWB MAC that includes a distributed reservation protocol (DRP) for distributed reservation of the medium (310). The invention also relates to any wireless system (300) that uses a MAC protocol comprising a distributed reservation protocol. The method comprises devices (301) announcing medium reservations in beacons (400) and devices (301) that receive such announcements respecting the reservations.

Description

SYSTEM AND METHOD FOR A DISTRIBUTED RESERVATION PROTOCOL WITH CONTROL OF ACCESS TO BAND MEDIUM ULTRAAMPLIA Field of the Invention The present invention relates to a protocol for ultra-wide band (UWB) access control to the medium (MAC). More particularly, the present invention relates to an improved protocol for UWB MAC. More particularly, the present invention relates to an improved UWB MAC protocol comprising a distributed reservation protocol (DRP). The invention also relates to any wireless system using a MAC protocol comprising a distributed reservation protocol. Background of the Invention Wireless personal area networks (WPANs) can not provide the network infrastructure of a typical wireless local area network (WLAN). However, some existing WPANs such as Bluetooth or IEEE 802.15.3 depend on the central unit as the "Device Network Coordinator". This makes the management of the topology more complex and eventually leads to different types of REF: 172785 dispositives. A distributed MAC protocol eliminates the need for a network infrastructure by distributing functions across all devices, ie. say, the nodes. There is no access point or central coordinator for a decentralized personal area wireless network (WPAN). That is, all devices in a decentralized WPAN exhibit the same protocol behavior and have the same "equipment / program capabilities. Asynchronous and isochronous data transfers are supported in most WPANs. While in Bluetooth and IEEE 802.15.3 the isochronous transfer is organized by the coordinator of the device network, it is handled in a fully distributed manner in the present invention. In the present invention, all the devices announce their use of airtime via beacon transmission, they recognize the use of airtime of the neighboring devices when receiving their radio beacons, and respect the use of airtime of the others devices before transmitting / receiving data. This makes the distributed MAC protocol very suitable for ad hoc applications and interconnection between peer entities. Additionally, the reservation of the medium by the devices on which the distributed MAC is based eliminates the perception and collision times in the medium. Due to the distribution of the reservations of the medium, continuous streaming support can be guaranteed in real time. A highly efficient real-time streaming protocol allows the controlled distribution of real-time data, such as audio and video. The data sources may include live data feeds, such as live audio and video, and stored content, such as pre-recorded events. A real-time streaming protocol (RTSP) for distributed MAC can be designed to work with established protocols, such as RTP and HTTP. The data throughput is increased and the support of the mesh-type network interconnection is significantly improved. The Multi-Band OFDM Alliance (MBOA) is currently standardizing a new MAC protocol for UWB. The authors of the present invention have created the baseline for this new standard and contributed most of the text of the present invention to the MBOA specification.

According to this invention and the associated MBOA standard, all devices are required to regularly transmit a beacon 105, in order to maintain coordination between the communication devices. The beacon 105 provides basic synchronization for the network and transmits information with respect to isochronous reservations. The protocol-specific parameters that have been chosen by MBOA are a superframe 100 with a length of 65,536 [usec], which consists of 256 Medium Access Intervals (MAS) where each MAS length is 256 [sec]. The MAS intervals are from 0 to 255 and the MAS interval 9 is the first interval. Several types of ranges are defined depending on how MASs are used by the device or nearby devices. Before communication can be established, a device must create its. own radio beacon group or join an existing group of beacons. For each phase 102 of beacon (also known as a beacon period or BP), 8 consecutive ± MAS intervals are used as beacon intervals, where all devices transmit their beacon beacons 105. The start time of a superframe 100 is determined by the start of a period 101 radiobeacon and is defined as a start time of the radiobeacon period (BPST) and the MAS intervals are numbered in relation to this start time. When a device initiates a new beacon group, it defines the limit of the superframe at any time interval that does not collide with other reservations of the time intervals of the beacon groups. A sophisticated distributed reservation protocol or DRP is needed to better support applications sensitive to delays and to provide access efficient to the medium in the distributed MAC. The system and method of the present invention provide a DRP that is compatible with the objectives of the distributed MAC. An important feature of the distributed MAC protocol and "of the present invention is that the reservations are broadcast by the receiver of a packet or a burst of packets.This avoids the problem of covert terminals, which otherwise hinders efficient operation in the Mesh network interconnection scenarios The sender and eventually the neighbors of the receiver and transmitter also broadcast the reservation In the distributed MAC protocol, time is divided into superframes 100, as illustrated in Figure 1, at the beginning of each superframe 100 there is a beacon interval / phase also known as a beacon period (BP) 101 which is followed by a data transmission interval / phase 102. A plurality of beacons 105 within the BP 101 is separated by a space short inter-frame (SIFS) plus mRadiobalizaGuardiaTiempo 104. The devices that are planning the transmission of data, propose a future start time in the l time for transmission, duration of transmission, priority of transmission, etc., to the proposed recipients of the planned transmission. The start time and The duration can be signaled 'either in the form of a start time interval and the number of time slots or in the form of a bitmap, in which, for example a. "1" indicates the time intervals proposed for the reservation. Two variants of channel time negotiation are considered: explicit DRP negotiation and implicit DRP negotiation. In the explicit variant, a "Request for Reservation" management box dedicated by the issuer is used to start the negotiation. The receiver evaluates whether the medium is free on the receiver side during the planned transmission time in the future. In order to be able to carry out this evaluation, each device / node stores locally the reservations of all the other devices, for example, in a bitmap. If the receiver does not have another reservation stored for the proposed period, the receiver transmits a positive response to the issuer of the Reservation Request. A "Reservation Response" management box dedicated for this purpose is used. In the event that the receiver is not willing to accept the transmission or in the case that the receiver has another reservation stored during the planned time, the receiver transmits a negative Reservation Response to the issuer. In this negative Reservation Response, the receiver may optionally propose alternative times for the planned transmission. These alternative times can also be signaled in the form of the start time interval and the number of time slots or in the form of a bitmap, in which, for example, a "1" points to the possible intervals of time on the receiver side If both the sender and the receiver have successfully negotiated a reservation, both devices include the reservation information in their respective beacon boxes in the subsequent MAC superframe 100. The beacons 105 are transmitted in the BP 101 at the beginning of a superframe 100, see Figure 1. The sender and receivers include reservation information on their beacon 105 to inform all devices surrounding the sender and receivers about the next transmission. reservation information in the beacon 105 of another device, record, ie store, this reservation information locally, for example, in a bitmap, and objection of any means of access at the announced point of time in the respective channel (eg, sequence of jumps) and during the duration of the planned transmission. In other words, the locally stored reservation information is used by a device to determine the free time in the wireless medium for its own transmissions in which the device is either a sender or a receiver. a transmission. For their own transmissions, the devices select periods in which the reservations of other devices are not recorded, that is, stored locally. BRIEF DESCRIPTION OF THE INVENTION In a preferred embodiment, the Reservation Request, Reservation Response, announcement process in the beacon frames of the devices included and the subsequent data transmission is illustrated in Figure 2. The MAC superframes 100 initiate at regular intervals, known as "beacon period start times" (BPST) or alternatively "target beacon transmission times" (TBTT) 201. In a given superframe 100, an emitter transmits a Reservation Request 202 during the phase 102 of data transmission of superframe 205 and a single receiver (in the case of a unicast connection) or multiple receivers (in the case of a multicast connection) respond in the same super-frame 205 with a Reservation Response 203. If successfully negotiates a reservation, both the issuer and the receivers include reservation information on their beacons 204 in BP 1 01 of superframe 206 subsequent. In the case of implicit negotiation, the Reservation Request and Reservation Response boxes are skipped and reservation information is included directly in the issuer's beacon. If the receiver detects that its identifier of device (ID) or the ID of a multicast group, in which it is participating, is included in a beacon for a current that does not exist before, it also implicitly responds by including reservation information for this current in your beacon. It may include either the same reservation information and thus accept the purpose or include the information at alternative intervals / times or deny the request. In the event that a receiver has proposed alternative times, the issuer may either accept the alternative and include the respective reservation information in its beacon or initiate a new proposal that reflects the availability of the receiver (possibly in the subsequent superframe). The protocol of the present invention allows the dynamic reservation of transmissions in each superframe 100. However, in order to save the overload of the reservation request and reservation response message exchange, in the preferred embodiment of this invention, it is automatically interpreted a reservation as a reservation not only for the subsequent superframe 206 but also for all of the following superframes In the case in which an issuer wishes to change a reservation, the issuer distributes new reservation information in its beacon 105. In the case of explicit DRP, the sender or receiver may terminate a reservation by sending a Reservation Termination box. In the implicit case, the reservation can be determined either by removing the DRP information from the beacon or by transmitting a reservation for the same current with zero duration. Upon receipt of a Reservation Termination box or a reservation information element absent on a radio beacon (or a reservation of zero duration), the devices suppress their corresponding, locally stored reservation information. In the event that a device receives reservation information for a time in the future for which the device is currently attempting to reserve the medium itself, only the device is allowed to distribute its own reservation if the priority of its planned transmission is greater than the priority of the reservation received. In the case of equal priorities, the medium is reserved based on a random number (such as for example the current identifier) or on a Jbase of the first to come, first to be served. If a device detects that its own reservation predominates or passes over another device, it cancels your planned transmission and try to make a new reservation in a subsequent superframe. All other devices enter the reservation with the highest priority (or, for example, the lowest random number) in their reservation table stored in a local memory 308. In summary, the following rules apply whenever a device attempts to reserve the medium: (1) if the medium is already reserved by a device, another device can never pass over this reservation; and (2) if two devices attempt to make a reservation in the same superframe, the reservation with the highest priority (or the smallest random ID of the stream in the case of equal priorities) prevails. BRIEF DESCRIPTION OF THE DRAWINGS These and other features of the system and method of the present invention will become apparent from the following figures and detailed description of the present invention. Figure 1 illustrates a complete layout of superframes; Figure 2 illustrates an overview of a MAC protocol operation; Figure 3A illustrates a wireless network of devices configured according to the present invention; Figure 3B illustrates a device configured to perform decentralized access control of the medium according to the present invention; Figure 4 illustrates a structure of a beacon frame of a device; Figure 5 illustrates a structure of a Capacity Information Element; Figure 6 illustrates a structure of a Radiobeacon Period Occupancy Information Element; Figure 7, 7A-7C illustrates a structure of a Distributed Reservation Protocol Information Element with alternative structures of the reservation information in sub-figure 7A, 7B, and 7C; Figure 8 illustrates a structure of a DRP Control Field; Figure 9 illustrates a Structure of the Radiobeacon Period; Figure 10 illustrates a structure of a DRP Request Order and an Optional Complete DRP Order; Figure 11 illustrates a structure of a DRP Response Order; Figure 12 illustrates a structure of an Order of DRP termination; Figure 13 illustrates a Guard Tie; Figure 14 illustrates SIFS and Guard Time at the end of a DRP reservation with non-ACK; Figure 15 illustrates SIFS and Guard Time at the end of a DRP reservation with Imm-ACK; Figure 16 illustrates a Message Sequence Diagram (MSC) for a unicast reservation initiated by the sender; Figure 17 illustrates an MSC for the unicast reservation initiated by the receiver; Figure 18 illustrates an MSC for the multicast reservation initiated by the sender; Figure 19 illustrates an MSC for Unicast DRP Termination; and Figure 20 illustrates an MSC for Multicast DRP Termination. Detailed Description of the Invention It will be understood by persons skilled in the art that the following descriptions are provided for purposes of illustration, not limitation. An expert understands that there are many variations that fall within the spirit of the invention and the scope of the appended claims. The unnecessary detail of known functions and operations of the current description can be omitted so as not to obstruct the present invention. Figure 3A illustrates a representative personal area wireless network 300, to which the embodiments of the present invention will be applied. The networks include a plurality of wireless devices 301 of personal communication. In the traditional approach, each 301 device can join any ad hoc network within its electric radio range 302 and can therefore participate in more than BP. Each wireless device 101 within the WPAN 300 shown in Figure 3A may include a system that includes an architecture illustrated in Figure 3B. Each wireless device 301 may include an antenna 306 coupled to a receiver 302 that communicates over the wireless medium 310. The devices 301 each further comprise a processor 303 and a Distributed Reservation Protocol (DRP) Processing Module 304. For example, in one device, the processor 303 is configured to receive the receiver 302 a DRP Request Order 1000 of one or more DRP Information Elements 700, which has the corresponding beacon positions and to process the Request 1000 Order of DRP using the DRP Processing Module 304 to negotiate a reservation and transmit data according to the outcome of the negotiation. In one device, the processor 303 is further configured to use the DRP Processing Module 304 to format a DRP Response Command 1100 that the processor then sends via the transmitter 306 to a receiving device to respond to a reservation request when specifying the params shown in Figure 11. Additionally, reservations successfully negotiated as well as received in the radio beacons by the wireless device 301 are stored in a persistent storage or bitmap 305 of DRP for use by the processor 303 and the Processing Module 304. DRP in the response to future reservation requests and in the planting of the future reservations. Similarly, a Reservation Table 308 stored in a local memory is used to store the received reservations made by the device 101. In a preferred embodiment, during a BP 101 all devices that are either in an active state or in a normal mode of energy saving transmit their own beacon 105. The body of a beacon frame 105 comprises the following fields and information elements (IE), as illustrated in Figure 4: - Interval Number 401; - Device Identifier 402; - MAC 403 address; - a certain number of Information Elements (IE) 404. The Interval Number 401 represents the interval, in which the beacon is transmitted. The invention also applies to a system, in which they are possible multiple radio beacon periods within the same superframe in order to support more devices. However, by simplicity assurance a radio beacon period is assumed in the following. Device ID 402 is a relatively short ID (eg 16 bits) which is derived for example from the 48-bit MAC address (or 64 bits). ) of the device (or chosen at random) and has the purpose of saving overload when the device is addressed. The MAC address 403 is the compladdress of 48-bit MAC (or 64-bit)) of the device. The Elements of Information- (IE) 404 can be of different types. The type of information elements can be identified by the Information Element Identifier (ID). The examples of IE that are described in more detail in this invention are the following: Device Capability Information Element (DEV-cap); - Beacon Position Occupancy Information Element (BPOIE) and Information Element (IE) ) of Distributed Reservation Protocol (DRP) DEV-cap information element contains information regarding device capabilities and is illustrated in Figure 5. Element ID 501 identifies IE, Length 502 gives the length of the IE and Capacity Code 503 identifies for example in the form of a bitmap what capabilities the device supports. It is pointed out that figures 4, 5, 6, 7, 8, 10, 11 and 12 have a tendency from right to left. The Radiobeacon Position Occupancy Information Element (BPOIE), illustrated in Figure 6, contains the 'Element ID 601, length information of IE 602, length information of the complete Beacon Period (in the case that the Radio Beacon Period is of dynamic length), 603, the additional fields 604 that are not specified here (and are only mentioned to illustrate that additional fields are in line with the present invention) and finally a list of fields of. information 605 of radio beacon intervals. A radio beacon interval information field 605 indicates a received beacon 105 of another device in the respective range. Each radio beacon interval information field therefore includes the beacon interval (position) 607 and a short device ID 606 of the device that sends beacon 105. The beacon position occupation information element is required in each radio beacon 105 because other devices have to be informed if their own beacon has been received successfully or if A radio beacon collision has occurred. • The latter may be due to the fact that two devices have chosen at random the same position of beacon in a BP or due to a terminal problem of concealment in mesh network scenarios. In this last scenario, a device can receive two radio beacons 105 from different devices in the same position in a BP 101 if these other two devices can not be heard from each other and are not aware of the beacon position of the other devices. The distributed reservation protocol information element (IE DRP) includes in the beacon whether the device is either a transmitter or a receiver of a future transmission in the data transmission phase 102 of this superframe 100. In an alternative mode, The DRP ID is also included in the radio beacons of direct neighbors of the transmitter and the receivers. In a preferred embodiment, a DRP IE is formatted as illustrated in the figure. Element ID 701 identifies the information element as a DRP IE. The Length field 702 gives the length of the DRP information element in number of objects. This is used to indicate the beginning of the next IE. The Details- of DRP 703 are illustrated in a separated in Figure 8 and include the following fields: Bit Tx / Rx 801 is set to 0, if the device is the transmitter of the planned transmission and is set to 1 if the device is a receiver. The Tx / Rx bit is only decoded if the reservation is of the hard type or the soft type. In an alternative embodiment of this invention, the Tx / Rx bit is used to indicate whether the current is unidirectional (for example unrecognized) or bidirectional. If the current is unidirectional, the issuer may not necessarily have to include the reservation information in its beacon. In an additional mode, the Tx / Rx bit is not present in the DRP IE, because it can not be strictly required. Policy Bit ACK 802 is set to 0 for uni-broadcast reservations with No-ACK policy and for multicast or broadcast reservations, and is set to 1 for uni-broadcast reservations with Imm-ACK policies or B-ACK. The type field 803 indicates the type of the reservation and is coded as shown in Table 1.

Table 1.- Type of Reservations The Priority 804 of the transmission can have a value between 0 and 7, where the priority is chosen according to Annex H.2 of IEEE 802. Id. The Current ID 805 is a randomly chosen value that identifies the current of the transmission. data and is used to distinguish multiple streams between the same set of emitter and receivers. Channel Number 806 is adjusted to the channel number used for data transmission. In the case that data transmission and beacon transmissions are always carried out in the same channel, this field is obsolete, shown here for integrity. The Destination DEVID / Source 704 is set to the DEVID of the receiver, the broadcast ID or multicast group, in case the device is the transmitter of the transmission, and it is the DEVID of the transmitter in the case that the device is a receiver in the planned transmission. - A Reservation Block 707 contains the information of the reserved times, rsp., Time intervals within the superframe. Several ways are possible to signal reserved times. Three example encodings of a Reservation Block are illustrated in the Figures 7A, 7B and 7C. Other ways can be thought, that do not change the essence of the present invention. Multiple Reservation Blocks can be included in a DRP IE. This is useful for signaling more than one reservation in an individual DRP ID. In a first mode, shown in Figure 7A, the reservation is given by BPST Deviation (or alternatively TBTT Deviation or reservation period) 705 and Duration 706. The BPST Deviation (or Deviation or TBTT period) defines the start time of the planned transmission. It is adjusted to the interval number of the first reservation interval, which is defined in relation to BPST. In an alternative mode (for example, for systems without intervals) the deviation of BPST is given in multiples of symbols (312.5 ns). In yet another modality, the Deviation is not defined in relation to the Start Time of the Radiobeacon Period but in relation to the Target Radiobeacon Transmission Time (TBTT) of the radio beacon of the device. In an additional mode, the Deviation field gives the Deviation between two consecutive reservations, that is, the period of the reservation. Duration 706 contains, in multiples of data intervals, the duration of the reservation. In the alternative mode, the duration is given in multiples of symbols (312.5 ns).

In a further embodiment of the invention, the starting point and the duration of the reservation are signaled by a Map of .bits 708, in which one or more bits are describing the state of each MAS, as shown in Figure 7B . In the case of an individual bit per MAS, the starting point of the reservation is given for example by the first MAS with a "1" in the bitmap and the length is given by the number of consecutive "1" in the bitmap. As an example only, both previous modalities can be combined in a generalized Reservation Block, as illustrated in Figure 7C, where the reservation period as well as the bit map are combined. In a reservation field of the most general form, a Reservation Type field 708 can indicate if the reservation is periodic with multiple times reserved by superframe or if the reservation reserves an individual time period in the superframe. Essentially in the case of individual reserved period by superframe, the reservation type field can also indicate if the reservation is only valid within the respective superframe or if it is also valid for all the following superframes until the reservation is completed. In order to combine the reservation period and bitmap, for example 256 intervals of the superframe can be divided into M blocks, where M is the minimum period possible of the reservation. The Period 710 field then gives the reservation period as a multiple of the minimum reservation period. The field of Deviation 711 gives the deviation of the block that includes the first reservation (for periodic reservations), rsp., An individual reservation, in number of blocks. Bitmap field 712 indicates in the form of a bitmap the reserved intervals within a reservation block. In this way, the generalized structure of the reservation field is a combination of bitmap concepts and deviations. It is noted that the DRP IE may contain additional elements or have a different structure without changing the essence of the present invention. An example of a potential additional field can be for example a field indicating whether the DRP negotiation was successfully completed. Devices that intend to participate in communication with other devices employ a BP access mode to send a beacon during a BP 101. A device does not transmit frames other than beacons 105 during a beacon period. A device scans the beacons 105 of the other devices during its BP 101. A BP can be of dynamic length (with one maximum length given) and consists of a certain number of MAS intervals. Each MAS interval contains 3 radio beacon intervals of duration mRadiobalizalntervaloLongitud. The beacon frame length can not exceed mMaxRadiobalizaLongitud. mRadiobalizalntervaloLength = mMaxRadiobalizaLength + SIFS + mRadiobalizaGuardiaTiempo This means the radio beacons 105 within a BP 101 are separated by a "short inter-frame space" (SIFS) 104 plus mRadiobalizaGuardiaTiempo. A variable BP 101 has the considerable advantage that the overload of the beacon is minimal in typical cases of an emitting device and one or more receiving devices. If a new device is attached, the network listens to at least a first complete beacon interval and evaluates the information contained in the beacons 105. Of the received beacons 105 as well as the BPOIE contained therein, the new device deduces the occupied beacon positions . In the same or the following superframe 100 (depending on the processing speed of the device), the device transmits its beacon in one of the free intervals of beacon or the annexed to the end of the BP, thereby increasing the size of the BP. If two devices have chosen the same position / additional beacon number, for example, they have joined the network in the same superframe 100, the devices detect the collision in the next superframe 100 by the absent BPOIE. In this case, a device re-transmits its beacon _ 105 in superframe 100, which follows its last attempt, in a different free interval of beacon. In a similar way, the BP can also be reduced in size if a device has left the network and its beacon interval has become free. For each radio beacon period, a device maintains a bitmap to store the occupation of the beacon intervals and the associated DEVID. A radio beacon interval is marked as occupied in the bitmap, if: a) a beacon is received during that interval; or b) the beacon interval is included in the BPOIE received from a device in the same beacon group. A range of occupied radiobeacon to unoccupied is changed, if: a) a beacon has not been received in the interval during consecutive superframes, mMaxRadioBoost losses, and b) the interval information has not been included in the BPOIEs received from any device in the same beacon group during the consecutive supermarkets mMaxRadioRadios losses. The devices send their beacon 105 in the same beacon range in subsequent superframes unless a collision occurs. The devices employ a radiobeacon collision resolution protocol (BCRP) to resolve the beacon interval selection collisions.

The devices include the BPOIE in all radio beacons 105. At the reception of a beacon box, a device saves the DEVID of the transmitter and the interval number where the beacon is received. This information is included in the BPOIE sent by the beacon device in the following superframe. Only the information of the beacons received during a superframe 101 is included in the BPOIE sent in the following supercard. If the DEVID of the device is absent in the BPOIE of a neighboring beacon during the consecutive supermaps mMaxRadioRadios losses, the device changes the beacon interval to a subframe interval in the next superframe. The reservations of DRP, and they do not need to be re-negotiated if the beacon interval is changed. The devices can radiolocate in multiple periods of radio beacon. The devices maintain a separate bitmap for each group of beacons. A BPOIE is calculated independently for each beacon group, and the device sends the BPOIE for each beacon group in the corresponding beacon period. If a neighboring BP 101 is detected, the device includes a DRP 700 IE of the BP reservation type on its own beacon. The DRP reservation extends through the ranges of MAS that the neighboring BP 101 is-_ using. Devices' that receive a beacon that includes a DRP reservation of the BP type, scan neighboring BPs. If, during the scanning process, a neighboring BP is detected, a DRP 700 reservation of the BP type is included in its own beacon. The DRP reservation extends through the ranges of MAS that the neighboring BP is using. The peer entity devices that wish to communicate, a beacon on the same BP 101. If a transmitting device communicates with the devices that radiobalise on (different) BP 101 because they are members of a radio beacon group, the device transmitter beacon in these multiple BP 101. The devices periodically scan beacons on all existing BPs 101 in order to maintain the status of existing reservations, and potentially resolve collisions. The devices scan all radiobeacon periods to determine existing reservations before making a new reservation or changing a reservation. The devices may optionally send beacons at neighboring BPs 101 to announce changes to reservations. The reservations received from neighboring BP 101 are recognized following the same rules as for reservations within the Radiobeacon Group of the devices. If the existing DRP reservations collide with a BP 101, the BP 101 has the highest priority, and therefore existing DRP reservations are renegotiated. If two or more BP 101 collide, devices with colliding radio beacons seek empty gaps that do not collide. Optionally, a device can start a new BP 101 at other vacated intervals. A BP 101 is terminated, and therefore the BP reservation can be debugged, when beacon 105 is not received during that BP 101 for at least the consecutive superframes 101 mMaxBirdBoost losses. In a preferred embodiment, a period is allowed of individual beacon by superframe. If two previously separate groups of devices and their associated beacon periods come in the range, they have to merge into a period of individual radio beacon. This period of individual beacon is located at the beginning of the superframe. The rules to explore other radiobeacon periods and protect them with BP reservations are not needed for this modality but can be applied in the transition phase during the fusion of the radiobeacon periods. As described in the summary of the invention, the DRP protocol of the present invention allows for the explicit or implicit negotiation of reservations. In the explicit case, reservations are established by a DRP Request and DRP Response order or an entry in control contact. In an alternative mode, a three-way contact input is used, in which a DRP Request and a DRP Response are followed by a DRP Complete box, which is sent by the same device that sends the DRP Request box. In the explicit case, a reservation is terminated by a table of DRP termination. In another aspect of the invention, this DRP Termination box is repeated by all devices that have also previously announced the reservation. In still another aspect of the invention, it is terminated a reservation by including a DRP IE with zero duration or by removing the corresponding DRP IEP. In the implicit case, the entry into contact is carried out implicitly by including a DRP IE in the beacons of the sender and the receivers and order / control boxes are not sent in advance. The DRP Request Order 1000 may be used to request or modify a DRP beacon. The DRP Request Order 100 is formatted as illustrated in Figure 10. Each DRP IE 700.n field included in the Order 1000 DRP Request corresponds to a non-contiguous DRP request. Each DRP 700 IE is n formatted as defined above for Figure 7. The Current ID is set to the same value in each DRP IE 700.n. The DRP Response Command 1100 is formatted as illustrated in Figure 11. The value of the Current ID 1103 is copied from the IE 700. DRP n of the DRP request. Reason Code 1104 indicates whether a DRP request was successful or not successful. The codes that can be assigned to this field are: 0 = Success 1 = Channel time not available 2 = Supervelocity requested, not supported 3 = Negated Response 4-255 = Reserved During a unicast DRP negotiation, if the Reason Code is set to l, the device includes the Availability Bitmap 1105 in the DRP Response Order. The 1105 Availability Bitmap can also be included for all other reason codes, although it is not necessary. During a multi-diffusion DRP negotiation, the device includes the 1105 Availability Bitmap in the DRP Response Order for Reason 0, 1 and 2 Codes. Again, the 1105 Availability Bitmap can also be included for all other reason codes, although this is not necessary. Field 1105 of Availability Bitmap contains 256 bits. Each bit corresponds to a range of MAS. A value of 1 indicates that the MAS is not available for the DRP assignment. A value of 0 indicates that the MAS is available for the DRP. The definition of the bits can also be reversed in an obvious way. In an alternative mode, the bitmap also includes more than one bit per MAS. In alternative modalities, in which the starting point in the duration of the reservation in the DRP IE are signaled by means of a bitmap or a combination of deviation and bitmap, the responder can also include all or part of a DRP IE in the DRP Response box instead of the Availability Bitmap. The optional DRP Complete order, which is sent in an alternative embodiment of the invention by the same device that has initiated the negotiation with the DRP Request box after the DRP Response has been received, has the same format as the DRP Request command, in Figure 10. The DRP Termination command is formatted as illustrated in Figure 12. The Current ID indicates the distribution identifier of the DRP that is terminated. In a preferred embodiment, a second access mechanism to the medium based on access based on containment is further defined as the DRP access. This access based on contention can be used for all MAS intervals, which have not been previously reserved by the DRP protocol. Access based on contention can also be used as a withdrawal access mechanism for traffic that is using DRP in the case that a reserved channel time is not useful, for example, for reasons of interference, and it is necessary to establish a new reservation In the case of the DRP access method, the negotiation of a reservation is activated by a current dependent on the application established and carried out during or after the establishment of the top layer stream. Nevertheless, the DRP negotiation should not be considered as a connection establishment but only a channel time negotiation procedure. The negotiation can be repeated, that is, it changes the allocated channel time, at any time during the lifetime of a stream. The DRP of the present invention allows the devices to make a reservation for one or several periods of the data phase 102 of a superframe 100. The reservation - guarantees periods of time for transmission, defined by a start MAS interval and a duration of MAS intervals, a bitmap or a combination of these formats. Reservation mechanisms can be used, for example, to save energy and / or isochronous QoS. All the devices that are senders or receivers of the DRP reservations announce their reservations in their own radio beacons 105. Another type of reservation is a special type of hard reservation for other periods of radio beacon. This is useful for other devices to detect the presence of strange radiobeacon periods. In a preferred embodiment, different reservation types: hard reservations, and soft reservations and reservations of BP 101. Hard reservations are equivalent to a TDMA interval. Soft reservations can be used to allow the reuse of unused reservation time. The type of reservation is announced in the DRP Information Element 700 included in a radio beacon 105, as well as in the DRP 1000 Order of Request box in the case of an explicit DRP negotiation. All the devices decode the radio beacons 105 and the DRP IE 700 and follow the access rules specified for each type of reservation. In a hard reservation only the owner of the reservation can have access to the medium, even if the medium is unoccupied. Other devices are only allowed access to the medium after the sender and receivers have released the unused reservation. During a hard reservation the sender and the receivers of the given data transfer may not need to exchange RTS / CTS boxes before data transmission since the medium is already debugged around the sender as well as the receiver by the IE 700 DRP included in radio beacons 105. In a soft reservation period, other devices may have access to the environment following access rules based on contention or argumentation.

The reservation owner can have access to the medium with the highest priority and without backtracking. Although the reservation mechanism must exclude all conditions, it may still be possible for a device to not receive reservation information, in which case the perception of the carrier can eliminate a potential collision. In an alternative embodiment of the invention, even the owner of the reservation has to perceive the medium for a certain duration. The soft type of reservation is especially useful, if the sender does not use its previously reserved time intervals. In this case, the ranges are still accessible for other devices in contention mode. The reservations of the Period of Radiobaliza can be considered like a special type of hard reservation.

They are useful to protect strange periods of radio beacon (during the transition phase before the radiobeacon periods are merged or in the case where multiple periods of radiobeacon per superframe are allowed) and to indicate the presence of the radiobeacon strange period to neighboring devices. Additional types of reservations are possible and are within the scope of the present invention; Guarding times are required to prevent collisions of transmissions on reservations adjacent. In addition, a SIFS time is required to ensure sufficient lap time between transmissions. A reservation is defined by the start MAS interval 705 and the duration in the MAS intervals 706, as specified in the DRP IE 700. The guard time is the time between the end of a reserved period and the start of the next reserved period. Including SIFS as part of a reserved period and assigning guard time between the reserved periods ensures that the transmissions are separated by at least one SIFS. Figure 13 is an illustration of how the guard time. it is assigned such that the transmissions are separated by at least one SIFS 1301 if the owners of the adjacent reserved periods derive from each other. The required guard time depends on the maximum drift between the local DEV times. This drift is a function of the time elapsed from a synchronization reference event. Each device maintains a nominal beacon period start time (BPST), which serves as a time reference. A device adjusts its BPST in order to maintain synchronization of superframes with the neighbor with the slowest clock in its beacon group. The device measures the difference between the real time in which the radio beacons of each neighbor are received and the expected times. The difference is positive, if the neighbor has a slower clock. Subsequently, the device delays its BPST by the maximum difference to all the neighbors in it. radio beacon group. The guard time is the sum of possible maximum drifts (which depends on the minimum clock accuracy) and the SIFS time. Within a hard reservation, - a device begins its transmission at the beginning of the first MAS of the reservation based on its local clock. In a soft reservation or alternative modalities, the transmission may have been processed for a time of exploration. Within the reservation, the sender can send as many packets as he wishes, that is, also a burst of data packets, in which packets are separated for example by SIFS pause times. The receiver may not recognize the DATA frames (Figure 14), recognize each individual DATA frame by an immediate ACK frame (Imm) (Figure 15), or recognize a burst of DATA frames by a burst / delayed ACK frame . The burst / delayed ACK frame contains information that recognizes each preceding data packet, thus allowing selective rejection of failed frames. The issuer assures that the time required by the access time (in the case of soft reservations) the packet burst such that the ACK and the final SIFS time do not exceed the duration of the reservation. In the event that a transmission of another device has blocked a certain interval during the reserved interval, the sender reduces the amount of data sent accordingly in order to guarantee the termination of the program transmissions. Because the clock in a DEV can be faster and another can be slow in relation to the ideal time, a DEV waiting to receive either a beacon 105 during the BP 101 or a frame during a reservation is DRP begins to receive before from the time it calculates that it is the beginning of BP 101 or the DRP Reservation and continues to receive after the time it calculates that it is within a SIFS of the end of BP 101 or DRP reservation. The amount of time that the DEV listens before the start of the DRP or BP 101 reservation and after the end of the DRP or BP 101 reservation is up to the implementer. There are two mechanisms for negotiating a channel time reservation: an explicit negotiation by means of order / control boxes of Dedicated DEV Request / Response 1000/1100 (and optionally DRP Complete), and an implicit negotiation by inclusion of the IE 700 DRP in the radio beacon 105 of the transmitter and receivers. The reservation is negotiated between the issuer and the recipients of the planned transmission. Once the reservation is established, the reservation information is included in the beacon 105 of the sender as well as the receivers in each superframe 100, in which the reservation is still active. This is necessary in order to inform the neighboring devices the sender and receivers about the existing reservation. The beacon 105 of the emitter and the receivers of a DRP stream are sent in the same BP 101. However, reservations are defined through the BP 101. Therefore, the devices scan all the BP 101, to determine the existing reservations, before initiating a new DRP negotiation or changing an existing reservation. Additionally, the devices periodically scan more beacon 105 in all existing BPs 101 in order to maintain the status of existing reservations, and potentially resolve collisions. In a preferred embodiment, there is only one radio beacon period, which has to be scanned, rsp., Decode. Each device announces on its beacon 105 whether it is capable of explicit DRP negotiation using the DRP Request / Response 1000/1100 Command / Response boxes and whether it is capable of implicit DRP negotiation by inclusion of the DRP IE 700 in radio beacon 105. A device does not initiate a DRP negotiation with a device that does not supports the respective DRP negotiation mechanism. The devices that are not capable of neither the implicit negotiation nor the explicit DRP, however, respect the negotiations that announce in the DRP IE 700 of the radio beacons 105 of the other devices. The explicit DRP negotiation makes use of the DRP Orders sent using for example an access mechanism based on containment (but can also be sent for example within a reservation already negotiated). An explicit unicast negotiation can be initiated either by the sender or receiver of the planned transmission, although negotiation initiated by the sender is the preferred embodiment of the invention. An explicit multicast negotiation can be influenced only by the broadcaster of the multicast group. The sequence of messages used during the unicast negotiation initiated by the sender is illustrated in Figure 16, the sequence of messages used during the uni-broadcast negotiation initiated by the receiver in Figure 17. The sequence of messages used during the multicast negotiation initiated by the sender is shown in Figure 18. The alternative mode with an entry in three-dimensional contact is not explicitly illustrated as the initiator sending an additional DRP Complete box at the end of the sequence to confirm the termination of the negotiation.

The negotiation initiated by the receiver is analogous to the negotiation initiated by the issuer with the only difference that an individual bit in the Order / Control DRP 1000 box of DRP is set to "0" instead of "1" to indicate that the device is proposed to be the receiver instead of the emitter of the current. The device can request multiple DRP reservations for the same stream simultaneously with an individual DRP negotiation. In each DRP IE 700, a start MAS interval, specified in the BPST Deviation field, and a duration, in multiples of the MAS intervals are proposed. The ID of the Current in each DRP IE 700 is set to the same value, which is chosen randomly in the first adjustment of the current or is given by an upper layer while ensuring that the ID of the Current is unique for the pair of devices (or set of devices in the case of a multi-broadcast connection).

The initiator chooses the MAS intervals of the proposed reservation based on their locally stored information, thus respecting the existing reservations and considering the availability of the receivers. Upon receipt of a DRP Petition with a Unidiffusion destination DEVID, the device responds with an Imm-Ack box followed by an order / control DRP Response box. The DRP Response order is sent using the containment-based access after the Imm-Ack has been sent "and the request has been processed.If the Imm-Ack is not received, the sender can retransmit the DRP Request box in the access mode based in contention Once the DRP Request Order 1000 is sent, the device waits for mDRP Final Proposal If a DRP Response 1100 Order is not received within a mDRP End Time after the request is sent, the device may retransmit Order 1000 of DRP Request In the reception of a box 1000 of Order / Control of Request of DRP, in which the DEVID of the receiver corresponds to the ID of a group of multi-diffusion to which the device is subscribed, the device does not correspond to an Imm-Ack box The device answers the order with a DRP Response Order 1100, for example in contention-based mode The receiver of Order 1000 of the DRP Request evaluates, if the medium its T á free if during the time requested during the locally stored information. If the medium is free and the device has no transmission or reception is programmed during the requested time, the device can correspond to the DRP Response Order 1100 with a status code equal to success and thus is recognized positively the DRP Petition. If the recipient of the DRP Request Order 1000 can not accept the request due to conflict with other reservations, the reason code in the DRP Response Order 1100 is set "channel time unavailable". The DRP Response Order 1100 includes the Availability Bitmap in this case to announce the available intervals for DRP. Upon receiving the channel time not available in the DRP Response Order 1100, the issuer of the DRP Request Order 1000 may restart the negotiation process with a new Order 1000 of DRP Request with a time corresponding to the Availability of the receiver. If the recipient of a DRP Request Order 1000 finds that the medium is busy during the proposed observation time and if an alternative period can not be identified, the receiver of the DRP Request Order 1000 answers - with a Response Order of DRP with the reason code set to "denied request". The reason code can also be set to "denied request", in case the recipient is not willing to accept the reservation for some other reason. In the event that the DRP Request 1000 is sent by the issuer of a multicast group, this issuer may receive multiple 1100 Response Orders from DRP. Some of the answers may indicate 'unsuccessful' negotiation. The sender may attempt to choose a reservation period that is possible for a maximum number of receivers based on the Availability Bitmap in the DRP Response boxes. The receivers that can not be served during the best possible reservation period can be served in separate periods of uni-broadcast or multi-diffusion reservation. These reservations need to be established by separate DRP negotiations. If the sender and the receivers have successfully negotiated a reservation, they include the reservation information in their respective beacons 105 in BP 101 of the subsequent 100 superframes. In an alternative embodiment of the invention, only the receivers include the reservation information in their beacon. This will be possible, for example, in the case of a uni-directional connection. In an additional mode, the receiver and all its direct neighboring devices (1-hop) include reservation information in its beacon. In yet another mode, the sender, the receiver as well as all the direct neighbors (1-hop) of the sender and receiver include the reservation information in their beacon.

In the event that each sender or receiver of a uni-broadcast stream or the sender of a multi-stream stream wishes to change the reservation, either it can initiate a new Order 1000 of DRP Request and the exchange of message of Order 1100 DRP Response or use the implicit DRP negotiation using the DRP IE 700s on their beacons 105. A unicast DRP negotiation using the DRP IE 700s on beacon 105 (called implicit negotiation) may already be initiated either by the sender or the receiver of a planned transmission, although the negotiation initiated by the sender is the preferred embodiment of this invention. An implicit multi-broadcast negotiation can only be initiated by the multi-broadcast group broadcaster. With implicit DRP negotiation using IE DRP 700 in beacon 105, DRP Request Order 1000 or DRP Response Order 1100 is not sent before the inclusion of the DRP IE 700 in beacons 105 of the emitter and receiver of the current. This type of DRP negotiation is therefore suitable for devices, which do not support channel access based on contention. A device only initiates an implicit DRP negotiation, a device that supports at least implicit DRP negotiation. The devices that support the DRP negotiation explicit by the DRP order / control tables also support the implicit DRP negotiation. There may be devices that do not support the negotiation of implicit DRP. A device can initiate a negotiation of Implicit DRP by including a corresponding DRP IE 700 in its beacon 105. The "Tx / Rx" bit in the DRP IE is set to "0", if the device is proposed to be the transmitter of the planned transmission and set to "1", if the device will be a receiver. "DEVID field 703 of Destination / Source is set to the DEVID of the communication partner For new currents, the Current ID is set to a value that is not currently in use for this set of devices. 700 of DRP is sent in a BP 101 in which the communication partner is being radioballed.The latter rule is obsolete if there is only an individual BP, as in the preferred embodiment of the present invention.A device that supports implicit DRP negotiation. it scans all the beacons 105 of its own BP 101 for the occurrence of its DEVID in the DEVID field 704 of Destination / Source of all the DRP IE 700. If the DEVID 704 of Destiny / Source corresponds to the DEVID itself, the device verifies if Current ID 805 is already in use for communication with the emitter of the beacon 105. An 805 Current ID that is not in use indicates a new implicit DRP negotiation. The case of implicit DRP negotiation for the purpose of modifying an existing stream is also treated with a new implicit DRP negotiation. A proposed DRP IE 700 receiver on beacon 105 evaluates whether the medium is free during the requested time according to the locally stored information. If the medium is free and its own transmission or reception was not programmed during the requested time, the device can take the DRP IE 700 on its own own radio beacon 105 with the Tx / Rx 801 bit inverted and the DEVID of the communication partner in field 743 in the Destination / Source DEVID. This DRP IE is interpreted as positive recognition of the. Implicit DRP initiation. If a proposed DRP IE 700 receiver in the initiating beacon 105 can not accept the implicit request due to conflict with other reservations, alternative BPST or TBTT deviations 705 can be proposed in its DRP IE 700. You can also include a bitmap or a combination of bitmap deviation for this purpose. In the alternative embodiment of the present invention, in which the DRP IE already includes a bitmap, an additional bitmap is not required. The initiator of the implicit negotiation can accept one of the alternative reservation proposals and include it in the following radio beacons 105 or you can restart the negotiation process with a new reservation proposal. The latter is not required if the responder has included all possible BPST deviations and durations for example in the form of a bitmap on its beacon. The inclusion of all possible reservation times in the radio beacon of the responders is especially useful in the case of broadcast currents in order to allow the sender to find a common time for the reservation. The receivers that can not be served during the period of reservation finally chosen can be served in separate reservation periods of uni-diffusion or multi-diffusion. These reservations need to be established by separate DRP negotiations. If a proposed receiver of the DRP IE 700 in the beacon 105 initiates, finds that the medium is busy during the proposed reservation time and if an alternative period can not be identified, or if the device is not willing to accept the reservation by for some other reason, it takes the DRP IE 700 on its next own beacon 105 with the 801 bit of Tx / Rx inverted, the DEVID of the communication partner in the DEVID field 704 of Destination / Source, and the 706 Field of Duration is adjust to zero. 'This DRP IE 700 with Duration of 706 set to zero is interpreted as a negative acknowledgment of the implicit DRP initiation. In this case, the initiator does not need to restart the implicit DRP negotiation. If the sender and the receivers have successfully negotiated a reservation, they keep the reservation information in their respective beacon boxes 105 in BP.101 of the subsequent superframes 100. In an alternative embodiment of the invention, only the receivers include the information of reservation on your beacon. In an additional mode, the receiver and all its direct neighboring devices (1-hop) include the reservation information in its beacon. In an alternative mode, the sender, the receiver and. all direct neighbors (1-hop) of the sender and receiver include reservation information in their beacon. In the case that either the sender or the receiver of a uni-broadcast stream or the sender of a multi-broadcast stream wish to change the reservation, they can initiate a new implicit DRP negotiation. Current ID 805 of the previous stream can be maintained. This is the reason why a device that supports an implicit DRP negotiation checks all DRP IE 700s received from their own existing streams for changes in the reservation fields (for example, Duration 706, BPST Deviation 705 or TBTT) (and field 806 of optional Channel Number). A changed DRP IE 700 is treated the same as a new implicit DRP enunciation. If a neighboring BP 101 is detected, a DRP IE 700 of the Duro type and the BP type is included in the beacon 105 to protect the neighboring BP 101. The devices, which receive reservation information in beacon 105 of another device, store this reservation information locally and differ from any access to the medium at the advertised point in the time indicated by field 702 of BPST deviation or TBTT in IE 700 of the DRP. Only the owner of the reservation is allowed to access the medium at the beginning of a reserved period. It is possible for two independent sets of devices to carry out a DRP negotiation in parallel. In this case, reservation collisions occur, which have to be resolved. If a device receives reservation information for a time in the future, for which the device has reserved the same medium, the device can only allow its own reservation to be maintained if the priority of the planned transmission of the device is greater than the priority of the reservation received. In the case of equal priorities, the reservation of the transmitting device with the ID of the lower current. This is because the Current ID is selected randomly. If a device detects that its own reservation was exceeded by another device, it cancels its planned transmission and attempts to make a new reservation in a subsequent superframe 100. All devices modify their locally stored reservation information, in case they receive a reservation with a higher priority or lower DEVID for the same overlap period of time or period. A DEV terminates a reservation that was initiated by an explicit DRP negotiation by submitting the DRP Termination Order. The DRP Termination Order of a uni-diffusion stream is recognized with an Imm-Ack frame (see Figure 19). The DRP Termination Order does not have to be recognized in the case of a multi-diffusion DRP Termination (see Figure 20). In an alternative embodiment of the invention, not only the device that terminates the DRP but all the devices that have previously broadcast to the reservation in its beacon send a DRP termination command. Currents that were established by implicit DRP negotiation can be terminated by removing DRP IE 700 from beacon 105 or alternatively adjust the DRP IE Duration field to zero (or alternatively an all-zeros bitmap) and subsequently remove the DRP IE. An IE 700 of DRP absent in a correctly received beacon 105 is interpreted as the termination of the current. In an alternative modality, the mechanism can also be used in place of the DRP Termination Order to terminate the flows that have been established by explicit negotiation. Once the DRP is completed, all DEVs included debug the DRP IE 700 from its beacon 105. If a beacon 105 is received with an DRP IE 700 absent, all devices can debug any local information regarding the reservation. associated with the absent DRP. Yes a DEV does not receive a beacon 105 that includes one or more DRP IE 700 during consecutive frames of mOxRadioBoost losses, the DEV debugs the reserved DRP times advertised on that beacon 105. While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that the management table, the device architecture and the methods as described herein are illustrative and various changes and modifications and equivalents may be substituted by elements thereof. without departing of the true scope of the present invention. further, many modifications can be made to adapt the teachings of the present invention to a particular situation "without departing from its central scope." Therefore, it is proposed that the present invention is not limited to the particular embodiments described as the best mode contemplated for The present invention includes all the modalities that fall within the scope of the appended claims. It is noted that in relation to this date, the best method known to the applicant to carry out the present invention is that which is clear from the present description of the invention.

Claims (37)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. Method of decentralized control of access to the medium in a communications network that includes a plurality of devices, characterized in that it comprises the steps of: dividing the time in a sequence of at least one superframe; and a first device of the plurality that transmits in the superframe at a target beacon transmission time (TBTT), a beacon box that includes a reservation for a transmission planned by an emitting device during the superframe. Method according to claim 1, characterized in that: the first device is the transmitter of the planned transmission; and which further comprises the steps of: a. the sender that includes the reservation in a radio beacon box in all the superframes during which the reservation is active, and b. which includes, by a device receiving the planned transmission, the reservation in a radio beacon box in all the superframes which is active reservation. 3. Method according to claim 1, characterized in that it further comprises the step of grouping the beacon frame transmitted by each of the plurality of devices in the superframe as at least one period of beacon that has a starting point at one time. start of radio beacon period (BPST) and followed by a phase of data transmission. 4. Method according to claim 1, characterized in that it also comprises the step of before a new negotiation, or a change of an existing negotiation, of the emitting device, the issuing device that negotiates with a receiving device of the transmission that is planned during the reservation. Method according to claim 4, characterized in that the negotiation step comprises the steps of: a reservation initiating device transmitting a distributed reservation protocol (DRP) request message comprising at least one reservation description selected of the group consisting of: a start time, and a duration indicated by the displacement of BPST or TBTT, a reservation period, a bitmap indicating the reserved times, at least one time slot number, a plurality, a channel / high indicator, and a code sequence; and in response to the DRP request, the negotiation step further comprises the passage of at least one reservation receiving device that transmits a distributed reservation protocol response message (DRP) that includes an indicator selected from the group consisting of the proposed reservation is accepted, the proposed reservation is rejected with an alternative reservation proposal and the proposed reservation is rejected without an alternative proposal. 6. Method according to claim 5, characterized in that the negotiation step further comprises the passage of at least one receiving device that also includes in the DRP Response, one of the points selected from the group consisting of at least one of proposal alternative time available for reservation and information of at least one alternative available time during the superframe. 7. Method according to claim 1, characterized in that it also comprises the step of including in the beacon box of the first device, a time of beginning of the reservation with respect to a point of selected reference of the group consisting of the TBTT of the first device, the BPST of the radiobeacon period in which the first device is transmitting the beacon box, the beginning of the superframe, a time period of the superframe, and a time interval of the superframe . Method according to claim 7, characterized in that: the start time of the reservation is given in relation to the reference point in the following superframe, in the. which will transmit the first device its next radio beacon frame; and if it is proposed by the receiving device, at least one alternative available time for reservation is given in relation to a reference point in the following superframe, in which the receiving device will transmit its next beacon frame. 9. Method according to claim 1, characterized in that it further comprises the step of maintaining for each device of the plurality a table of all the planned reservations received or sent by the device. Method according to claim 1, characterized in that it also comprises the steps of: a receiving device of the reservation that sends a poll packet to the sending device; in the reception of the polling packet, the sending device that sends at least one data packet to the receiving device; and receiving device that recognizes the reception of at least one data packet when transmitting an acknowledgment packet. Method according to claim 1, characterized in that it also comprises the steps of: defining the superstructure as comprising a plurality of time intervals of access to the medium; and defining a reservation as a start time interval of the plurality of media access time slots and a duration as a number of media access time slots. Method according to claim 1, characterized in that it also comprises the step of: defining the superframe as comprising a plurality of time units; and define a reservation as a start time in units of time and a duration as a number of units of time. 13. Method according to claim 1, characterized in that it also comprises the steps of: defining the superframe as comprising a plurality of time intervals of access to the medium; and defining a reservation as at least one bit in a bitmap comprising at least one bit for each medium access time interval of the plurality of media access time slots. Method according to claim 1, characterized in that it also comprises the steps of: defining the superframe as comprising a plurality of time intervals of access to the medium; and defining a reservation as at least one element selected from the group consisting of a reservation period, a reservation displacement, a reservation period shift, a reservation duration, a bitmap of at least one access time interval to the middle and a reservation time. Method according to claim 1, characterized in that it also comprises the step of defining a reservation as an element selected from the group consisting of: - a plurality of reservations per superframe and valid for a single superframe, a plurality of reservations per superframe and valid for a plurality of superframes, individual reservation by superframe and valid for a single superframe, and individual reservation by superframe and valid for a plurality of superframes. 16. Method according to claim 6, characterized in that at least one alternative available time for the reservation is signaled by means of a? Availability bitmap having at least one bit per time interval to indicate the availability of the interval 17. Method according to claim 6, characterized in that at least one alternative available time for the reservation is signaled by means of at least one element selected from the group consisting of reservation period, reservation displacement, period displacement. reservation, duration of reservation, bitmap having at least one bit per time interval to indicate the availability of the time interval 18. Method according to claim 2, characterized in that it also comprises the step of implicitly negotiating the reservation using a first beacon box of the emitting device and a first frame radio beacon of the receiving device. 19. Method according to claim 1, characterized in that it also includes the step of including availability information in a radio beacon box of a device 20. Method according to claim 5, characterized in that it also comprises the step of the initiating device that completes the negotiation with a transmission of a complete DRP message. 21. Method according to claim 5, characterized in that it also comprises the passage of the issuing device terminating the reservation. 22. Method according to claim 21, characterized in that it also comprises the passage of a device terminating a reservation that is initiated by an explicit negotiation, by transmission of a termination order. 23. Method according to claim 22, characterized in that it also comprises the passage of the receiving device which recognizes the determination order of a unicast current by transmission of a frame of Immediate Recognition (ACK Imm). Method according to claim 22, characterized in that it also comprises the step of sending a termination order for all the devices that have previously included the reservation in a beacon frame. 25. Method according to claim 2, characterized in that the radio beacon frame of the steps of transmission and inclusion comprises an information element (IE) of the distributed reservation protocol (DRP) that includes information regarding the position of at least one reservation in the superframe. 26. Method of compliance with the claim 22, characterized in that it also comprises the step of terminating a reservation by performing one of the selected sub-steps of the group consisting of: removing the reservation IE from a current beacon frame and all subsequent radio beacon frames, And set the duration field of the reservation IE to zero in a current beacon box and remove the reservation IE from the subsequent beacon frames. 27. Method according to claim 1, characterized in that: the transmission step includes in the beacon frame the information of a reservation selected from the group consisting of a starting point and duration and a bitmap; and the inclusion step is optional. Method according to claim 1, characterized in that it also includes the step of respecting the reservation for all the devices that receive a table radio beacon that includes the reservation. 29. Method according to claim 1, characterized in that it further comprises the steps of: including information in a direction of the planned transmission in the beacon box; and only devices within a transmission interval of a receiving device that respects the reservation, in the case of a planned unidirectional transmission. 30. Method of compliance with the claim 25, characterized in that only the transmitting device performs the inclusion step to include the reservation IE in the beacon box. Method according to claim 25, characterized in that only the receiving devices and all the neighboring 1-hop devices of the receiving devices perform the inclusion step to include the booking IE in the beacon box. Method according to claim 25, characterized in that the sending device, the receiving devices and all neighboring 1-hop devices of the sending device and the receiving devices perform the inclusion step to include the reservation IE in a beacon frame . 33. Method of compliance with the claim 54 27, characterized in that it also comprises the receiving device of a reservation that performs the steps of: in case of a Soft Reservation, which initiates its own transmission if the sending device does not use the reserved time; in the case of a Hard Reservation, that does not access means and the device transmitter of the planned transmission does not use the reserved time; and in the case of a Reservation of Period of Radiobaliza, that only reserves the time for the transmission of radiobaliza. 34. Communications network, characterized in that it includes a plurality of devices that include reservations for planned transmissions in its beacon boxes when performing the decentralized access control method to the means of claim 1. 35. Wireless device that reserves the means of a Distributed manner, characterized in that it comprises: an antenna for sending and receiving messages on a wireless medium; a receiver coupled to the antenna to receive messages transmitted on the wireless medium; a transmitter coupled to the antenna to transmit messages on the wireless medium; a distributed reservation processing module to perform the distributed reservation of the medium; a processor for dividing the time into a sequence of at least one superframe, each superframe having at least one beacon period starting at a Target Broadcast Period Start Time (BPST) and including at least one beacon interval, the radiobeacon period that is followed in the superframe by a data transmission phase, and is coupled to: i. the transmitter and the receiver for sending and receiving, respectively, beacon frames during the beacon and data period during the data transmission phase of the superframe. ii. the distributed reservation processing module for a. manage the occupation of the radiobeacon interval and the reservations of the data transmission phase; b. format a beacon frame for transmission in at least one beacon interval, such that the beacon frame includes a reservation of the medium by the device for data transmission during the data transmission phase and c. format a beacon box for the transmission in at least one radio beacon interval corresponding to the reservations received on the medium. 36. "Wireless device according to claim 35, characterized in that: each superframe further comprises a plurality of media access intervals assigned between the radiobeacon period and the data transmission phase, and further comprising: a. bitmap operably connected to the processor and arranged to have at least one bit corresponding to a range of the plurality of access intervals to the medium, and b) a memory operably connected to the processor and arranged to store a memory table. reservation of all planned reservations received or sent by the device, and the distributed reservation protocol (DRP) processing module is further configured to adjust and readjust at least one bit of the bitmap according to the reservation of the medium for the transmission of data and the occupation of radiobeacon intervals, and b.to store and suppress sent reservations and received by the device in the memory reservation table. 37. Wireless device for the distributed reservation of the medium, characterized in that it comprises: an antenna for sending and receiving messages on a wireless medium; a receiver coupled to the antenna to receive reservation messages of the transmitted medium on the wireless medium; a transmitter operatively coupled to the antenna to transmit the reservation message of the medium on the wireless medium; a distributed reservation processing module for distributed reservation of the medium; and a processor coupled to the distributed reservation processing module, a distributed reservation protocol bitmap, and a memory including a DRP reservation table, the processor for performing the method of decentralized access control claim 1 to using the distributed reservation processing module, the DRP bitmap, and the DRP reservation table.