Communication techniques

Abstract

A communication device (15), wherein the communication device (15) is configured to transmit and / or receive a plurality of packets using a schedule related to a reference time; wherein the communication device (15) is configured to transmit synchronization information (81a, 81b); wherein the communication device (15) is configured to include, in the synchronization information (81a, 81b), timing information defining a timing of transmission of the synchronization information (81a, 81b) with respect to a reference time. A communication device (16 ', 16' '), wherein the communication device (16', 16 '') is configured to receive synchronization information (81a, 81b); wherein the communication device (16 ', 16' ') is configured to transmit and / or receive a plurality of packets using a schedule related to a reference time, and wherein the communication device (16', 16 '') is configured to evaluate timing information which is included in the synchronization information (81a, 81b) and which defines timing of transmission of the synchronization information (81a, 81b) with respect to the reference time in order to perform synchronization.

Description

Technical Field

[0001] In the following, techniques for communication between at least one first communication device and at least one second communication device are disclosed. For example, the second device may be an arrangement (e.g., with a wireless front end, such as an optical front end, such as VLC communication), and at least one first device may be one or more devices (e.g., wireless devices, such as optical devices). In some examples, the arrangement (or the second device) is fixed (at least in one or more front ends) and the one or more first devices may be mobile. Synchronization techniques are particularly discussed. Variable MAC scheduling for real-time optical communication is also disclosed. Background Art

[0002] Wireless communications (e.g., visible light communications, VLC, and other communications, such as radio frequency, RF, communications, ultrasonic communications, etc.) are known, for example, between an arrangement (e.g., with a fixed repeater or front end) and one or more devices (e.g., mobile devices).

[0003] In some cases, a carefully designed medium access strategy is necessary: ​​authorized time slots can be allocated to each communication device, thereby avoiding conflicts in transmission. In some cases, contention-based time slots can be provided, for example, for new communication devices to join the communication network. This requires the use of complex synchronization techniques between devices. In some cases, it has been decided to use beacon signals, which are periodically transmitted by the master communication device (which can also be a scheduler) to the other communication devices. Beacon signals are also important for transmitting control signaling from the master communication device to the other communication devices.

[0004] However, some problems are still encountered. In fact, there is a waiting time from the transmission of the beacon signal and for each communication device to handle synchronization. This means that before receiving the beacon signal and handling synchronization, the communication device cannot perform communication and the communication device needs to wait for a period of time.

[0005] Furthermore, different traffic conditions (and different switching properties, e.g., different levels of urgency) cause congestion in some cases: some important packets experience high delays, resulting in unacceptable latency. Summary of the invention

[0006] The invention is defined in the independent claims.

[0007] By means of the present independent claim, the above-mentioned problem can be solved or at least alleviated. Specifically, the synchronization information (including the timing information) can be scheduled at the most appropriate time position. In some cases, the synchronization information (or even any control signaling) can be delayed, anticipated or even skipped. Thus, if a lot of application data (e.g. uplink or downlink application data, e.g. for emergency communications) is to be transmitted, the synchronization information can be delayed (or even skipped in some cases).

[0008] The present invention also allows for a less stringent synchronization method, as the devices may be synchronized to a time (eg, a timing reference or reference time) that is not necessarily the time at which the beacon signal is transmitted, and thus, synchronization information may be transmitted at any time.

[0009] It is important to note that synchronization is performed even if the synchronization information is delayed or expected.

[0010] According to one aspect, a communication device (eg, a second communication device, eg, including a coordinator) is provided.

[0011] wherein the communication device is configured to transmit and / or receive a plurality of packets using a schedule associated with a reference time;

[0012] wherein the communication device is configured to transmit synchronization information;

[0013] Therein, the communication device is configured to include timing information defining the timing of transmission of the synchronization information with respect to the reference time in the synchronization information.

[0014] The communication device may be configured to include in the timing information the temporal distance from the transmission of the synchronization information and the reference time.

[0015] The communication device may be configured to include information about a time distance from a reference time to a next timing reference (eg, reference time) in the timing information.

[0016] The communication device may be configured to provide scheduling information to the different communication devices, allocating an exclusive time slot to each of the different communication devices.

[0017] The communication device may be configured to provide scheduling information to different communication devices, allocating exclusive time slots to the communication devices for transmission of at least some control signaling.

[0018] The communication means may be configured to further transmit at least some event driven control signalling.

[0019] The communication device may cause the control signaling to include at least synchronization information.

[0020] The communication device may be configured to delay or anticipate transmission of control signaling in the event that a higher layer application requires transmission and / or reception of the transmission.

[0021] The communication device can be configured to, in case a high-layer application requires transmission and / or reception of payload data, check whether at least some time slots are idle according to the schedule, and therefore delay or anticipate the transmission of control signaling in idle time slots in the same superframe, otherwise wait for the next superframe.

[0022] The communication device may cause the control signaling to include scheduling information for subsequent transmissions.

[0023] The communication device may cause the control signaling to include synchronization information for subsequent transmission.

[0024] The communication device may cause the control signaling to include announcement information.

[0025] The communication device may cause the control signaling to include random access timing information providing information about the grant-free time slot.

[0026] The communication device may cause the control signaling to include grant access timing information providing information about the grant-free time slot.

[0027] The communication device may be configured to define the scheduling information by taking traffic into consideration.

[0028] The communication device may be configured to define the scheduling information in the following manner:

[0029] In case of relatively high traffic congestion, reducing the number of time slots used for transmission of control signaling and / or increasing the number of granted time slots allocated to at least one of the different communication devices; and / or

[0030] In the case of relatively low traffic congestion, the number of time slots used for transmission of control signaling is increased and / or the number of granted time slots allocated to at least one of the different communication devices is reduced.

[0031] The communication device may be configured to rank the urgency of transmission and / or reception according to the urgency level, wherein the communication device is configured to

[0032] In case of a relatively high level of transmission and / or reception, reducing the number of time slots used for transmission of control signaling and / or increasing the number of granted time slots allocated to at least one of the different communication devices; and / or

[0033] In case of a relatively low level of transmission and / or reception, the number of time slots used for transmission of control signaling is increased and / or the number of granted time slots allocated to at least one of the different communication devices is reduced.

[0034] The communication device may be configured to define the schedule by resuming time slots for transmission of control signaling if a threshold condition is met.

[0035] The communication device may also include multiple front ends configured to transmit and / or receive different packets simultaneously through different front ends.

[0036] The communication device may be configured to selectively transmit synchronization information simultaneously for different front ends in different time slots.

[0037] The communication device may include a higher layer application or be connected to a higher layer application, the communication device using information about the characteristics of the real-time application data flow from the higher layer application.

[0038] The communication device may cause the information on the characteristics of the real-time application data flow to include one or more of the following: periodicity of the application data flow, maximum allowed delay, maximum allowed delay variation, and maximum allowed datagram loss rate.

[0039] The communication device may be configured to use the information about the characteristics of the real-time application data stream, for example in such a way that if the information about the characteristics of the real-time application data stream requires a certain maximum waiting time for transmission and / or reception of a particular transmission, time slots that are not scheduled for a specific different communication device are granted to a different communication device, and / or other transmissions from the communication device are transferred to subsequent time slots.

[0040] The communication device may be configured to transmit and / or receive the plurality of packets as wireless signals and to transmit the synchronization information in the wireless signals.

[0041] The communication device may be configured to transmit and / or receive the plurality of packets as optical signals, and to transmit the synchronization information in the optical signals.

[0042] According to one aspect, there is provided a communication method, comprising:

[0043] A plurality of packets are transmitted and / or received using a schedule relative to a reference time.

[0044] The method also includes transmitting synchronization information;

[0045] Wherein transmitting the synchronization information comprises including, into the synchronization information, timing information defining a timing of transmission of the synchronization information with respect to a reference time.

[0046] According to one aspect, there is provided a non-transitory storage unit storing instructions which, when executed by a processor, cause the processor to:

[0047] controlling transmission and / or reception times of a plurality of packets using a reference-dependent schedule;

[0048] Control the transmission of synchronization information;

[0049] The synchronization information includes including timing information defining the timing of transmission of the synchronization information with respect to a reference time into the synchronization information.

[0050] According to one aspect, a communication device (eg, a first communication device, such as a user equipment) is provided.

[0051] wherein the communication device is configured to receive synchronization information;

[0052] wherein the communication device is configured to transmit and / or receive a plurality of packets using a schedule associated with a reference time;

[0053] Therein, the communication device is configured to evaluate timing information in order to perform synchronization, the timing information being included in the synchronization information and defining the timing of the transmission of the synchronization information with respect to a reference time.

[0054] The communication device may be configured to evaluate information about a time distance from a timing reference to a next timing reference (eg, from a reference time to a next reference time) based on the timing information.

[0055] The communication device may be configured to resynchronize by comparing the time position of the measured reference time with the timing information.

[0056] The communication device may be configured to read the timing information to determine a time deviation with respect to the timing information and thereby modify the time determination using the time deviation.

[0057] The communication device may be configured to count the number of time slots between the current reference time and the start of the synchronization information and compare the counted number of time slots with the number encoded in the timing information to calculate the offset and compensate for the offset by adjusting its timing to the timing information.

[0058] The communication device may be configured to receive scheduling information allocating exclusive time slots to the communication device and allocating different exclusive time slots to different communication devices, so that the communication device transmits in the time slots allocated to it and avoids transmitting in time slots allocated to different communication devices.

[0059] The communication device may be configured to receive scheduling information allocating an exclusive time slot to the master communication device for transmission of control signaling, such that the communication device receives the control signaling in the time slot allocated for transmission of at least the control signaling.

[0060] The communication device may be configured to receive at least some event driven control signaling during unallocated time slots, and the master communication device may thus occupy the unallocated time slots to transmit at least some event driven control signaling without scheduling those event driven control signaling.

[0061] The communication device may cause the control signaling to include scheduling information for subsequent transmissions.

[0062] The communication device may cause the control signaling to include synchronization information for subsequent transmission.

[0063] The communication device may cause the control signaling to include announcement information.

[0064] The communication device may cause the control signaling to include random access timing information, providing information on grant-free time slots.

[0065] The communication device may cause the control signaling to include grant access timing information, providing information on grant-free time slots.

[0066] The communication device may be configured to include a high-level application or be connected to a high-level application, wherein the communication device is configured to receive payload data from the high-level application and transmit the payload data according to a schedule, and / or wherein the communication device is configured to transmit the payload data to the received high-level application according to a schedule.

[0067] The communication device may be such that a time slot not scheduled for said communication device is granted to said different communication device if information about the characteristics of the real-time application data flow defined by the higher layer application requires a certain maximum latency for transmission and / or reception of a certain transmission.

[0068] The communication device may be configured to evaluate, from the timing information, a time distance between the timing information at the time of encoding and a timing reference at the time of measurement.

[0069] The communication device may be configured to adjust the internal clock to the timing information at the time of encoding when a deviation occurs between the timing information at the time of encoding and the timing reference at the time of measurement.

[0070] The communication device may be configured to transmit and / or receive the plurality of packets as wireless signals and to receive the synchronization information in the wireless signals.

[0071] The communication device may be configured to transmit and / or receive the plurality of packets as optical signals and to receive the synchronization information in the optical signals.

[0072] According to one aspect, there is provided a communication method, comprising:

[0073] Receive synchronization information;

[0074] Use reference-dependent dispatch;

[0075] Timing information is evaluated in order to perform synchronization, the timing information being included in the synchronization information and defining the timing of transmission of the synchronization information with respect to a reference time.

[0076] According to one aspect, there is provided a non-transitory storage unit storing instructions, which, when executed by a processor, causes the processor to

[0077] Control the reception of synchronization information;

[0078] controlling transmission and / or reception of a plurality of packets using a schedule relative to a reference time;

[0079] Timing information is evaluated in order to perform synchronization, the timing information being included in the synchronization information and defining the timing of transmission of the synchronization information with respect to a reference time. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1 An example of wireless communication is shown.

[0081] Figure 2 An example of communication is shown.

[0082] Figure 3 An example of a support frame according to the present technique is shown.

[0083] Figure 4 An example of a frame containing synchronization information is shown.

[0084] Figure 5 An example of synchronization information is shown.

[0085] Figure 6 , Figure 7 , Figure 8 An example of syntax for a communication element is shown.

[0086] Fig. 9 An example of communication at the coordinator (base station) is shown

[0087] Fig.10 An example of a first communication device is shown. DETAILED DESCRIPTION

[0088] A preliminary description of some general examples

[0089] Figure 1A network 10 (also referred to as OWPAN, i.e., optical wireless personal area network described below, but which can be generalized to optical networks, or even wireless networks) is shown for wireless communication (e.g., optical communication, or visible light communication VLC) between at least one second communication device and at least one first communication device, the at least one second communication device being a communication device 15 (which can be, for example, a base station, BS) here. Here, the at least one first communication device includes at least one communication device (e.g., user equipment, UE, relay endpoint, REP, mobile device).

[0090] The second communication device (e.g., communication device) 15 may include or be a coordinator 12, which may be a computer-based system (e.g., a processor-based system). In some examples, the coordinator 12 may be understood as a (or one of) the intelligent parts of the communication arrangement 15. In the industrial automation example, the coordinator 12 may also be part of a fixed device, associated with some machines or coordinating (or associated to a device that coordinates) multiple machines.

[0091] The second communication device (communication arrangement) 15 may include at least one or more front ends (e.g., relay endpoints REP) 14a ... 14g. The front ends 14a ... 14g may be, for example, optical front ends (OFEs). In the case of OFEs, each OFE may include an optoelectronic transceiver, a photodiode, a transmission diode, a light emitting diode, an LED. In the case of RF, each front end may include an RF transceiver. In the case of ultrasound, each front end may include an ultrasound transceiver.

[0092] In an example, multiple front ends 14a...14g may be part of a communication device 15. The optical front ends 14a...14g may be spatially distributed (e.g., in known locations) to transmit and receive in different parts of an environment to transmit / receive communications over channels (e.g., optical channels) 18a...18g. In an example, the front ends 14a...14g may have fixed and / or known locations.

[0093] The front end 14a...14g of the second communication device 15 can be connected to the coordinator 12 via a fronthaul 17. The fronthaul 17 can be composed of (or at least include) communication channels (e.g., 17a, 17b...17g) for allowing transmission between the front end 14a...14g and the coordinator 12. The fronthaul 17 may include at least one communication network. The fronthaul 17 may support a star topology. The fronthaul 17 may include multiple point-to-point connections. The fronthaul 17 may be wired (e.g., using metal conductors) or cabled (at least for some connections), at least for connections to one front end (in some examples, all connections to the front end are wired and / or cabled). In some examples, the fronthaul 17 is wireless (at least for connections to one front end).

[0094] Reference numerals 18a ... 18g refer to optical channels (or more generally wireless channels) between the optical front ends 14a ... 14g and the first devices 16' and 16". The first device is also referred to as a first device device, a user equipment (UE), an endpoint (EP) mobile device, or a communication device. It can be seen that multiple front ends can transmit (simultaneously) to the same first device. For example, Figure 1 The front ends 14a, 14b, 14c are shown communicating with a first device 16' via channels 18a, 18b, 18c, respectively, while the front ends 14e, 14f, 14g are shown communicating with another first device 16" via channels 18e, 18f, 18g, respectively.

[0095] As will be explained in more detail later, communications are considered here to be defined in superframes (e.g., each superframe occupies a period of time, e.g., there is no superframe overlap, e.g., such that the end of a superframe ideally coincides with the beginning of the immediately following superframe). Figure 2 Superframe 1 and superframe 2 are shown. Each superframe can be divided into a series of time slots (e.g., each time slot occupies a time span, e.g., there is no overlap of time slots, e.g., such that the end of a time slot ideally coincides with the beginning of the immediately following time slot). Each superframe can be understood to include a series of mutually adjacent time slots (e.g., a superframe can be composed of an integer number of time slots). All time slots may be understood as having the same time length (although different superframes may have different time lengths), and the time length of a time slot is typically known to both the first communication device 16', 16" and the second communication device 15. On the other hand, different superframes may have different lengths (and the length of each superframe may be signaled, for example, by indicating, for example, how many "sync slots" there may be in each superframe, for example in the "sync slots" field of a synchronization element, also referred to as a "sync element", see below). A plurality of time slots form a slice (e.g., each slice occupies a time span, e.g., there is no overlapping of slices, e.g., such that the end of a slice ideally coincides with the beginning of the immediately subsequent slice). Each superframe may be understood as comprising a series of mutually adjacent slices (e.g., a superframe may consist of an integer number of slices). Different slices may have different lengths of the number of time slots, and this information may be signaled. In the example (e.g., in Figure 2 ), each slice (also referred to as a "block") can be assigned to a specific device (e.g., one of 12, 15, 16', 16") or a specific application (e.g., a high-level application 902, such as Fig. 9), the specific application runs in a specific device (e.g., one of 12, 15, 16', 16"). Some slices may not be used. The definition of the slices (e.g., identified by their time slots, such as by the first time slot of each slice) can be defined by the schedule and can be signaled, for example, in a GTS descriptor element (see Figure 8 and related descriptions) (the GTS descriptor element may be part of the schedule information 915). Thus, a superframe may be considered to be composed of a number of slices (eg, as defined by the schedule), and each slice may be considered to be subdivided into a series of time slots (eg, of equal length). Figure 2 The time slots are not shown, but the slices allocated to a particular granted communication are shown. A granted communication is in a GTS (Grant Time Slice). Figure 2 Blocks 82a...82h are shown to be allocated to application traffic A, and slices 83a, 83b, 83c are allocated to application traffic B. For the purposes of this description, it is important to define whether application traffic A and application traffic B are in the uplink (e.g., from the first device device 16' or 16" to the coordinator 12) or (from the coordinator device 16 to the first device device 16' or 16). For the purposes of discussing the present technology herein, in some examples, it is not important whether synchronization is performed in a granted time slot (GTS) (or granted time slice) or in a random time slot (RTS) (or random time slice). The GTS (or granted time slice) is defined by a scheduler (e.g., 910, see below), while the RTS (or random time slice) is transmitted in non-predefined time slices (e.g., based on event-driven access). In the example, the RTS can be scheduled by the scheduler 910, but transmissions from multiple devices (e.g., 16', 16", 15) can occur in the RTS. In contrast, only a single device can transmit in the GTS (coordinator or mobile device). In Figure 2 In the embodiment, slices 81a and 81b are occupied by synchronization information in the downlink (e.g. from the coordinator 12 towards the first device apparatus 16' and 16"). It will be explained later that the synchronization information (81a, 81b) can take the form of so-called "synchronization elements". The synchronization information 81a and 81b may include timing information (also called "synchronization time slot" or "synchronization time slot field", for example, which indicates in which time slot of the superframe the current synchronization information 81a or 81b starts). The "synchronization time slot field" thus provides information about when the superframe starts (e.g. by notifying in which time slot of the superframe the current synchronization information 81a or 81b starts). Thus, the synchronization element informs the first device 16' or 16" about in which time slot (e.g. the Nth time slot) of the superframe (starting from time slot 0) the frame containing the synchronization element is transmitted. Thus, the first device 16' or 16" can calculate the start of the superframe backwards (which is N time slots before the time slot in which the frame starts).

[0096] For example, synchronization element 81a may provide information regarding the timing at which superframe 1 has begun, and synchronization element 81b may provide similar information.

[0097] Figure 5 An example of synchronization elements 81a, 81b (synchronization information) is provided in Figure 5 , for example, a superframe number (e.g., a row-by-row number identifying a particular superframe) is shown to be encoded in a particular data field (shown in this example as being encoded as two octets, but a different bit length (macNumSuperframeSlots) may be used). The synchronization elements (synchronization information) 81a, 81b may include information about the total number of time slots in the current superframe, also indicated as being encoded as octets, but a different bit length (macNumSuperframeSlots) may be used, such as Figure 5 As shown, the synchronization elements (synchronization information) 81a, 81b may include a "synchronization time slot" ("synchronization time slot field"). The synchronization time slot ("synchronization time slot field") may be an example of timing information (in some examples, it will be understood that the number of time slots of a superframe and / or the superframe number may also be considered as part of the timing information). The synchronization time slot may be used by the communication devices 16' and 16" to synchronize their clocks with the clock of the coordinator 12. In fact, each of the first devices 16' and 16" may reduce the offset between its local clock and the time indicated by the synchronization time slot field (or more generally the timing information) within the synchronization element (or more generally the synchronization information 81a and 81b). To give just one example, in the example of the timing information 81b, information indicating t1 will be written, i.e., the distance from the beginning of superframe 2 (e.g., the number of time slots from the first time slot of the superframe to the first time slot of the synchronization information 81b).

[0098] In most examples, the synchronization elements (synchronization information) 81a, 81b are imagined to be transmitted at the very beginning of the superframe (and in this case, a "0" can be written in the "Sync Slot Field"). However, for generality, the position of the synchronization elements (synchronization information) 81a, 81b in the superframe can take different time positions.

[0099] It should be noted that the synchronization slot field may encode the time distance of the synchronization element from a reference time. The reference time may, for example, be the first time slot of the current superframe (this choice is for simplicity and also because the synchronization information 81a, 81b is usually meant to be transmitted in the first time slot of a superframe and a common value of the "sync slot field" is usually expected to be "0"). For example, the transmission of the synchronization information may provide the timing of a packet (e.g., the preamble of a packet) comprising the synchronization information 81a, 81b. Most of the time, in the example, the synchronization elements (synchronization information) 81a, 81b are meant to be transmitted at the beginning of the superframe and most of the time the synchronization slot field will be occupied by a 0 value. This will not happen if Figure 2 In the example of , this is only because, for generality, we prefer to indicate different time positions. Nevertheless, it will be appreciated that the synchronization element 81b (synchronization information) will provide an indication of t1, which may be the time distance from the start of superframe 2 (t1 may be indicated, for example, as the number of time slots from the first time slot of the superframe to the time slot corresponding to the start of the synchronization element 81b). Figure 4 The synchronization elements 81a, 81b (synchronization information) are shown. Here we see that the synchronization elements (synchronization information) 81a, 81b can be encapsulated in a PPDU (physical protocol data unit), which includes a preamble, a physical header and a PSDU containing synchronization elements. It can be seen that the start of the synchronization slot (indicated by 41) is Figure 5 The start of the synchronization slot 41 may be, for example, t1 in the case of 81b. By considering Figure 5 , (and the first devices 16 ′ and 16 ″ may also synchronize themselves with the clock of the coordinator 12 ).

[0100] However, it should be noted that in some examples it may be preferred not to keep a fixed position of the synchronization elements (or more generally the synchronization information). As mentioned above, the transmission of the synchronization information (synchronization elements) 81a, 81b may in principle result in delays of important application transmissions (e.g. scheduled or non-scheduled). For this reason, in some examples it is preferred not to keep a fixed position of the transmission of the synchronization elements (e.g. not necessarily at the first synchronization slot of the superframe), but in some cases it is preferred to allow for a mobile and definable positioning within the superframe. For example, we assume that in Figure 2In this case, the synchronization element 81b should be transmitted at time t0. In this case, it will not be possible to transmit the communication of the application traffic A indicated by 82e (e.g., payload data requested by a higher layer application (e.g., 902), see below). In the event that the communication 82e is urgent, the coordinator 12 may decide to delay the transmission of the synchronization element 81b so that it is transmitted at a subsequent moment t1 instead of at moment t0. For synchronization purposes, this is not a problem, since the moment t1 will be indicated in the synchronization timeslot field (as timing information) of the synchronization element 81b instead of at moment t0. The first communication devices 16' and 16" will simply resynchronize by taking into account the time distance between the start of the synchronization timeslot 41 (as indicated in the synchronization timeslot) and the start of the superframe 2 (when considered as the reference time here). For this reason, synchronization between the coordinator 12 and the first communication devices 16' and 16" will be authorized, and flexibility is also achieved: allowing the time position of the synchronization element to be selectively moved at a more appropriate time slice, thereby reducing the damage to the transmission of urgent communications. For purposes of the present discussion, determining whether transmission 82e is in the uplink or downlink is essentially unimportant. Transmission 82e may be an urgent, unscheduled transmission from coordinator 12 to communication devices 16' and 16", or it may be a scheduled transmission from one of devices 16' and 16" to coordinator 12. It is entirely possible to see that synchronization is maintained together without blocking fixed pieces of control information at the expense of high priority communications.

[0101] Overview

[0102] The contribution aims to allow, for example, optical communications with real-time low-latency behavior, e.g. for medium access based on Time Division Multiple Access (TDMA). The previous fixed structure with beacons, CAP (collision avoidance period) and CFP (collision-free period) (e.g. as defined in WO 2020 / 053235 A1) is broken so that there is a general concept of a time slice (TS) for reserving resources for various purposes. In this way, control information required for network operation can be transmitted at an arbitrary time within the TDMA superframe structure, allowing a scheduler (e.g. part of a coordinator) to schedule application data transmission at the required time.

[0103] The contribution applies to a network (e.g., 10) following a coordinated topology, i.e., a network consisting of (or more generally including) member devices (e.g., 16' and 16") and one coordinator device (e.g., 12). The coordinator is responsible for allocating channel time to itself and the member devices to facilitate interference-free transmissions.

[0104] This proposal provides deterministic transport to support real-time data streams through its channel access mechanism. Configuration of data streams is beyond the scope of this document and may require implementation-specific interfaces. The coordinator supports registered streams by scheduling transport resources accordingly.

[0105] The TDMA-based technology, through the proposed changes, provides a flexible medium access scheduling that allows supporting isochronous traffic. The coordinator 12 and the member devices 16' and 16" obtain the characteristics of the real-time application data flow through the interface. The information includes one or more of the following: periodicity of the application data flow, maximum allowed delay, maximum allowed delay variation, datagram size, maximum allowed datagram loss rate.

[0106] Different protocols exist to provide this information to the OWPAN devices (12, 16' and 16"). Furthermore, this information may be provided in an implementation-specific manner.

[0107] TDMA / Scheduled Medium Access

[0108] The optical network (OWPAN) 10 utilizes scheduled medium access. Scheduled medium access relies on specific frames (e.g., synchronization elements 81a, 81b, e.g., Figure 4 The coordinator 12 allocates channel time for channel access of different paths. Deterministic channel access is supported in the guaranteed time slice (GTS) and random channel access is supported in the random time slice (RTS).

[0109] NOTE—In some cases, RTS may be used for certain purposes only, such as association and requesting additional channel time resources.

[0110] In TDMA (i.e. scheduled channel access mode), the channel time can be divided into superframes (such as Figure 2 The superframe is further divided into consecutive groups of one or more time slots, called time slices, as shown in Figure 3 shown.

[0111] The time slices may be unallocated, allocated to a device as a guaranteed time slice (GTS), or designated as a random time slice (RTS). Allocating time slices is done by an implementation-specific scheduler that is part of the coordinator 12. The scheduler (as part of the coordinator 12) may allocate time slices for transmission to the coordinator and members 16' and 16".

[0112] During the GTS, devices 16 ′ and 16 ″ may (or in some examples should) perform deterministic medium access according to rules. During the RTS, devices 12 , 16 ′ and 16 ″ may (or in some examples should) perform random medium access.

[0113] While maintaining the OWPAN 10 with scheduled medium access, the coordinator 12 may (or in some examples should) transmit frames containing synchronization elements (eg, 81a, 81b).

[0114] A superframe consists of (or more generally includes) a total of macNumSuperframeSlots superframe slots. macNumSuperframeSlots is a variable determined by the OWPAN coordinator and announced to devices in a Sync element.

[0115] The superframe slot numbered zero may (or in some examples should) be the first slot in the superframe (this is not Figure 2 example, there should be no problem).

[0116] The present technique utilizes an integer number of superframe slots to specify a duration within a superframe, such as the duration of a GTS or RTS.

[0117] During the duration of the current superframe, each of these time slices in the superframe may be in one of the following states:

[0118] • Unallocated: No device can (or in some examples should) transmit in these time slots.

[0119] • Allocation as GTS: The coordinator allocates a time slice to a device using the GTS descriptor element. The corresponding device 16' or 16" may (or in some examples should) transmit during the GTS.

[0120] • Assign as RTS: The coordinator 12 assigns these slots as RTS using the RTS descriptor element. During RTS, the devices 16' and 16" can access the channel randomly via Slot ALOHA.

[0121] A device 12, 16' or 16" may (or in some examples should) avoid transmitting in superframe time slots not allocated to it. This applies in particular to devices 16' and 16", which are not allowed to transmit in time slots not allocated to devices 16' and 16". In some cases, the coordinator 12 may transmit important transmissions (e.g., high-level transmissions) in unallocated time slots.

[0122] Synchronize member devices (12, 16', 16") via coordinator 12

[0123] All members (e.g., 16' and 16") are synchronized to the coordinator clock (e.g., the clock of coordinator 12) and can (or in some examples should) be synchronized to the coordinator's clock before they start transmitting or receiving. The synchronization elements (e.g., 81a, 81b) transmitted by the coordinator 12 enable synchronization of members 16' and 16" for scheduled medium access by arrival time synchronization.

[0124] The coordinator 12 may (or in some examples should) maintain the value of macSuperframeNumber and increment it by one for each superframe that is started. The macSuperframeNumber value wraps around to zero after reaching a maximum value (e.g., it is a number associated with two octets, but different bit lengths may imply different maximum values). (65535).

[0125] The coordinator 12 may (or in some examples should) transmit a frame (eg, 81a, 81b) containing a synchronization element (eg, 81a, 81b) through each OFE (14a...14g) in the appropriate time slice. Figure 4 The receiver address of the frame may (or in some examples should) be a broadcast address. The frame may (or in some examples should) contain the current macSuperframeNumber, the number of time slots contained in the superframe (e.g., Figure 5 ), and the number of frame time slots (e.g., 81a, 81b) in which synchronization elements are contained is transmitted (e.g., Figure 2 t1 in, as indicated in the synchronization time slot, such as Figure 5 ). The coordinator may (or in some examples should) start transmitting frames at the beginning of a superframe slot.

[0126] Upon receiving a sync element (eg, 81a, 81b), members 16' and 16" may (or in some examples should) set their macSuperframeNumber and

[0127] The value of macNumSuperframeSlots is set to the value in the received sync element. In addition, members 16' and 16" can (or in some examples should) synchronize their clocks to the received sync elements 81a, 81b by reducing the offset between their local clocks and the time indicated by the sync slot field within the sync element (e.g., less than aPhyOfeSyncAccuracy).

[0128] If no synchronization elements 81a, 81b are received during the duration of a superframe, devices 16' and 16" can (or in some examples should) assume that the value specified for macNumSuperframeSlots in the last received synchronization element is still valid and increase macSuperframeNumber at the beginning of the next expected superframe. Therefore, the present technology tolerates the situation where synchronization elements 81a, 81b are not transmitted at all, thereby increasing reliability.

[0129] If no synchronization elements 81a, 81b are received within aMacMinSyndninterval, devices 16' and 16" may (or in some examples should) continue to listen for the next synchronization element in order to synchronize before attempting further transmissions. After more than 2*aMacMinSyndinterval have passed without receiving a synchronization element, devices 16' and 16" may be considered unsynchronized.

[0130] Random access in RTS

[0131] RTS may (or in some examples should) only be used for transmissions from a device to a coordinator during:

[0132] a) Association process

[0133] b) GTS request process

[0134] The slotted Aloha scheme can be used for contention-based access in RTS. Superframe slots in RTS are grouped into so-called RANDOPS, each of which contains a RANDOP length superframe slot. The number of superframe slots per RANDOP determines the slot size of the slotted Aloha scheme and therefore determines the effectiveness of collision prevention. The value of the RANDOP length is announced in the RANDOP length field of the RTS descriptor element.

[0135] RTS is signaled via the RTS descriptor element, transmitted from the coordinator to the members. For each received RTS descriptor element, the corresponding RTS may (or in some examples should) start with the superframe slot given in the RTS descriptor element and end after the number of slots given in the RTS length field has passed.

[0136] The number and duration of RTSs may be varied by the coordinator to allow more or fewer random access transmissions in a superframe.

[0137] NOTE—The coordinator 12 should periodically transmit frames containing RTS descriptor elements to allow association and prevent members 16' and 16" from exhausting transmission resources without being noticed.

[0138] The device requests additional resources during the GTS. However, when the device does not have any or only insufficient GTS time allocation to perform the GTS request, it can use RTS to transmit a GTS request element to the coordinator GTS grant channel access based on the Time Division Multiple Access (TDMA) principle.

[0139] Scheduled Medium Access in GTS

[0140] GTS allows channel access based on the principle of Time Division Multiple Access (TDMA)

[0141] The coordinator 12 may perform transmissions to the devices 16' and 16" at any point in the superframe, except when the devices are allocated a time slice (half-duplex).

[0142] If the coordinator 12 has control over multiple spatially distributed OFEs 14a...14g, it can allocate the same superframe time slot in different GTSs or RTSs to multiple spatially distant devices 16' or 16" in order to promote spatial reuse of superframe time slots within the OWPAN coverage area. In some examples, the coordinator 12 should allocate GTS and RTS in a way that transmissions in RTS do not interfere with transmissions in GTS.

[0143] All members 16' and 16", whether they are associated with the scheduled OWPAN 10 or attempting to associate, can (or in some examples should) synchronize with the coordinator's clock before they start transmitting or receiving. The synchronization elements 81a, 18b (e.g., Figure 6 ) (e.g., Figure 4 As shown) enables the devices 16' and 16" in the scheduled OWPAN 10 to achieve synchronization through arrival time synchronization.

[0144] Members 16' and 16" may (or in some examples should) assume that the start 41 of the preamble of the PPDU carrying the synchronization elements 81a, 81b corresponds to the start time of the synchronization slot as specified in the synchronization element. Therefore, the superframe starts the synchronization slot before the start of the preamble. All superframe slots and the timing within the superframe are relative to the calculated superframe start.

[0145] In order to prevent conflicts between transmissions of different devices, a guard time exists between consecutive GTSs. Its duration is calculated based on the clock accuracy and the synchronization element transmission rate as follows:

[0146] MaxDrift=aClockAccuracy*Syncinterval,

[0147] where aClockAccuracy is a MAC constant and Syncinterval is the interval between sync element transmissions and hence the periodicity of the sync events.

[0148] The coordinator may (or in some examples should) allocate GTSs with a constrained guard time of at least 2*(MaxDrift+aPhyOfeSyncAccuracy),

[0149] Located between two subsequent GTSs that are not spatially orthogonal.

[0150] OWPAN / Network Announcement

[0151] The coordinator 12 may (or in some examples should) begin transmitting announcement elements in appropriate time slices at least every aMaxAnnouncementPeriod.

[0152] The Announcement element may (or in some examples should) contain the current value of the OWPAN Name and OWPAN Name Length.

[0153] If the coordinator 12 uses multiple OFEs 14a...14g, the frame containing the announcement element may (or in some examples should) be transmitted through all OFEs 14a...14g.

[0154] Before attempting an association in the RTS, devices 16' and 16" may (or in some examples should) wait for receipt of an Announcement element. Upon receiving the Announcement element, devices 16' and 16" may (or in some examples should) update the value of their OWPAN names to the value in the received Announcement element. In addition, the device may (or in some examples should) apply change values ​​from any attribute change request elements contained in the same frame as the Announcement element. The values ​​contained in the Announcement element require association with OWPAN10.

[0155] Carrying frame and element information

[0156] We assume that the optical communication system uses a frame format that starts with a preamble and PHY header of the physical layer, followed by a second MAC layer header and payload. The MAC header distinguishes the payload type, and the actual payload consists of (or more generally includes) one or more elements.

[0157] Synchronous element

[0158] Synchronization elements or more generally, synchronization information 81a, 81b are provided in Figure 5 , for transmitting synchronization information from the coordinator 12 to the members 16' and 16", as part of the scheduled medium access, defined in Figure 6 middle.

[0159] Superframe number: The number of the current superframe in which the frame containing the synchronization element is transmitted.

[0160] Total number of superframe time slots: The total number of time slots contained in the current superframe.

[0161] Synchronization slot (or more generally, timing information): The slot in which the preamble of a frame containing synchronization elements is transmitted.

[0162] Figure 5 The example of has been discussed and its fields are overridden here.

[0163] Announcement elements

[0164] Figure 6 The announcement element depicted in is used to announce OWPAN as part of the OWPAN maintenance process.

[0165] OWPAN Name Length: The length of the following OWPAN Name field is in octets.

[0166] OWPAN Name: A human-readable name for the network, encoded as a UTF-8 string. This string may (or in some examples should) not contain null bytes at any position.

[0167] NOTE - OWPAN IDs may be bit-wise different but appear identical to humans due to possible homographs in the UTF-8 encoding.

[0168] RTS Descriptor Elements

[0169] Figure 7 The RTS descriptor element depicted in describes a single RTS allocation in beacon-enabled channel access mode.

[0170] RTS Starting Slot: This field specifies the first slot allocated for RTS.

[0171] RTS Length: This field specifies the duration of the RTS in a superframe slot.

[0172] RANDOP Length: This field specifies the number of slots in the RANDOP during the described RTS.

[0173] Validity Information: This field indicates how validity information for the GTS is signaled. See below for how to interpret the values ​​included.

[0174] ValidOnly: If this field is set to one, the GTS becomes valid in the same superframe the GTS Descriptor element is received. Otherwise, the GTS becomes valid in the following superframe. This field is present only if the ValidityInformation is zero.

[0175] Valid Superframe: This field specifies the superframe for which the GTS is valid. It is present only if the validity information is equal to 1.

[0176] GTS starting timeslot: This field specifies the first timeslot of the allocated GTS.

[0177] GTS Length: This field specifies the duration of the GTS in a superframe slot.

[0178] constant

[0179] The constant aMaxAnnouncementPeriod defines how many announcements must be sent at least every second.

[0180] aPhyOfeSyncAccuracy is defined to define the maximum deviation of the actual transmission time at the optical transmitter from the nominal transmission time as expected by the MAC.

[0181] The constant aMacMinSyncInterval with a value of 1s defines the minimum rate at which synchronization elements are transmitted per OFE.

[0182] Other aspects

[0183] The second communication device 15 [e.g., a master communication device, a communication device, a base station, or a coordinator, or a scheduler] may transmit control signaling. [The control signaling may include scheduling information and / or synchronization information (e.g., including timing information)] [The scheduling information may include a GTS descriptor element and / or an RTS descriptor element] [Multiple control signalings may be transmitted in at least one packet; they may be distinguished by various techniques, for example, by using a different preamble or in any case a different unique sequence for each control signaling].

[0184] At least a portion of the control signaling may be transmitted in a GTS exclusively allocated to the second communication device 15 [e.g., a master communication device, a communication device, a base station, or a coordinator, or a scheduler]. However, in an example, the control signaling (and in particular the synchronization information 81a, 81b) may be event-driven (e.g., transmitted only when necessary without having to schedule it) (e.g., it may be transmitted only in a different channel for transmitting at least some control signaling, and / or in at least one RTS; in some examples, other communication devices may always remain waiting to receive a transmission from the communication device during an unallocated time slot, and therefore, the communication device may occupy an unallocated time slot to transmit at least some event-driven control signaling without having to schedule those event-driven control signaling).

[0185] In the case of urgent transmission and / or reception of application frames, control signaling can be transmitted, for example, in an event-driven manner. Figure 2In one example, data transmissions 82a-82h (traffic A, e.g., assigned to the first communication device 16') and data transmissions 83a-83c (traffic B, e.g., assigned to another first communication device 16") are scheduled, while control signaling 81a and 81b may be event driven and transmitted in time slots not assigned to any transmission (and thus the second communication device 15 has the privilege to transmit control signaling 81a and 81b signaling in those unassigned time slots). It is worth noting that the scheduling in superframe 2 may be controlled by the control signaling transmitted in superframe 1. 81a. Internally, the second communication device 15 [e.g., a master communication device, a communication device, a base station, or a coordinator, or a scheduler] may foresee transmitting control signaling 81b in time slot t0. However, considering the high level of urgency of data transmission 82e, data transmission 82e takes over and control signaling 81b may be delayed to time slot t1. In the case where control signaling 81b also includes a timing element, if this is instantiated by the data value "SynchSlot", this value will be updated (e.g., t1 will be encoded instead of t0).

[0186] It should be noted that Figure 2 It also applies to the case where the control signaling 81b is actually scheduled for transmission at time slot t0. In this case, the transfer applies in any case. If it is transmitted only in the scheduling information of the control signaling 81a, the time slot starting from t0 will be allocated for traffic A and for transmission 82e.

[0187] In the above example, the second communication device 15 [e.g., the main communication device, communication arrangement, base station, or coordinator, or scheduler] may be connected to (or include) a higher-level application. The higher-level application may define the characteristics of the real-time application data flow through an interface. The information may include one or more of the following: periodicity of the application data flow, maximum allowed delay, maximum allowed delay variation, size of the datagram, maximum allowed datagram loss rate. For example, in Figure 2 In the example of , the maximum allowed delay for flow A (specifically transmission 82e) may require that transmission 82e be rescheduled to time slot t0, resulting in control signaling 81b being shifted to time slot t1.

[0188] (E.g., in some examples, when a transmission is said "at t0," it means "it starts at t0").

[0189] Communication example at coordinator 12

[0190] Fig. 9 An example of communication at the coordinator 12 (or more generally at the base station 15, or a second device communication arrangement) is shown in FIG. Here, an example of communication via OFE 14a, ..., 14g (eg, Figure 1) and the first device 16 'and 16 "exchange data with the high-level application 902. Specifically, follow Figure 2 For example, data A (traffic A) is transmitted in some specific slices (GTS) 82a, ..., 82h in the downlink and other data B (traffic B) is received in GTS slices 83a-83c. A scheduler 910 (which allocates different slices to different flows A and B and / or allocates different slices, i.e. consecutive time slots, to different devices) exchanges control data 913 with a high-level application 902. Scheduling information 915 can therefore be provided to the first device 16', 16" (for example, informing which slice is associated with which of the devices 15, 16', 16"). A synchronization information generator 920 (which generates synchronization elements 81a, 81b or more general signaling information, or even contains synchronization elements 81a, 81b) Figure 4 The synchronization information 920 may exchange control information with the scheduler 910. Fig. 9 A queue 930 is shown on which data and synchronization information 81a, 81b for slices 82a, ..., 82h (traffic A) are received from the high-level application 902 and the synchronization information generator 920, respectively. The data and synchronization information 81a, 81b for slices 82a, ..., 82h can be transmitted from the queue 930 to the first device 16', 16". Feedback information 931 can be received by the synchronization information generator 920 from the queue 930. In this example, consider Fig. 9 For example, each superframe is scheduled (e.g., Figure 2 This means that the synchronization element 81a is generated by the synchronization information generator 920 and is encapsulated and provided to the queue 930 and transmitted through the OFE 14a...14g according to the timing defined by the scheduler 910. Figure 2In superframe 2 of , the synchronization information generator 920 avoids transmitting the synchronization element 81b at time t0 to allow the transmission of urgent data (traffic A) in time slot 82e. Nevertheless, the synchronization information 81b is transmitted at time t1. However, as described above, in the timing information (e.g., the "synchronization time slot field") of the synchronization element 81b, an indication of the notification time t1 is provided (without providing information about time t0). It should be noted that this example is only one possibility. Specifically, feedback 931 is shown as being provided to the synchronization information generator 920 from the queue 930, but this may not be the case: the scheduler 930 can decide on the scheduling (including the scheduling of the synchronization element 81b) without having any feedback 931 from the queue 930 (but for example with urgent information from the high-level application 902). It is worth noting that the transmission of the synchronization elements 81a, 81b can be performed in the downlink without any problems, and in this case, the scheduler 910 requires scheduling of the GTS for the data received in the GTS slice 82e. The synchronization information generator 920 and the scheduler 910 may be connected ( 914 ) such that the scheduler may dynamically perform rescheduling taking into account, for example, feedback 931 .

[0191] Basically, it does not matter here whether the data to be transmitted at the time slot is uplink or downlink, or scheduled data or non-scheduled data: what matters is that the synchronization information 81b is transmitted at a time that can be selectively determined by the coordinator 12, but still allows synchronization of the second devices 16' and 16", increasing flexibility (but not at the expense of reliability).

[0192] The high-level application 902 may provide information about the characteristics of the real-time application data stream to the second communication device 15 (e.g., via an interface). The information about the characteristics of the real-time application data stream may include one or more of the periodicity of the payload data of the application data stream. Thus, the coordinator 12 will know how many times the payload data should be transmitted and / or received per superframe. The information about the characteristics of the real-time application data stream may include the maximum allowed delay (e.g., the maximum allowed delay variation) for transmitting the payload data of the application data stream. Thus, the coordinator 12 knows whether it is allowed to delay the transmission of the payload data or whether it is preferred to delay another data: for example, in Figure 2 In the embodiment of the present invention, the payload data (flow A) 82e may not be delayed (e.g. due to a maximum allowed delay for the transmission of the payload data), and therefore the transmission of the synchronization element (synchronization information) 81b is preferably delayed. In a variant, there may be a maximum allowed loss rate (e.g. of datagrams) instead of a maximum allowed delay. The information about the characteristics of the real-time application data flow may include (or may provide information that allows understanding) how many times per superframe the payload data should be transmitted and / or received. Therefore, the scheduler 910 may generate a schedule to allow the transmission of specific payload data.

[0193] In some examples, if information about the characteristics of the real-time application data flow requires a specific maximum latency for transmission and / or reception of a particular transmission (e.g., from and / or to a UE), then a time slot that is not scheduled for a particular different communication device (e.g., UE) may be granted to a different first communication device (e.g., by rapidly dynamically rescheduling), and / or other transmissions from the communication device (e.g., control signaling) may be shifted to a subsequent time slot [e.g., this may occur where a higher-layer application specifies some payload transmissions as having a high level of urgency].

[0194] Therefore, the operation of the scheduler 910 can be considered known. However, in some cases, the schedule can be defined based on some feedback. For example, the schedule can be operated so that:

[0195] In case of relatively high traffic congestion, reducing the number of time slots used for transmitting control signaling and / or increasing the number of granted time slots allocated to at least one of the different communication devices; and / or

[0196] In the case of relatively low traffic congestion, the number of time slots used for transmitting control signaling is increased and / or the number of granted time slots allocated to at least one of the different communication devices is reduced.

[0197] For example, traffic congestion may be measured by measuring round trip latency and / or error rate.

[0198] Additionally or alternatively, there is the possibility to rank the urgency of transmission and / or reception according to an urgency level, such that:

[0199] In case of relatively high levels of transmission and / or reception, reducing the number of time slots used for transmission of control signaling and / or increasing the number of granted time slots allocated to at least one of the different communication devices; and / or

[0200] In case of relatively low levels of transmission and / or reception, the number of time slots used for transmitting control signaling is increased and / or the number of granted time slots allocated to at least one of the different communication devices is reduced.

[0201] Examples of first communication devices 16 ′, 16 ″

[0202] Fig.10 Shows Figure 118g). The transmitter / receiver 25 may be internally connected to a high-level application 927 (e.g., via a line 25', such as a wired line). The high-level application 927 may therefore exchange payload data with a high-level application 902 of a second device 15 (and in particular a coordinator 12) via a network 10 (e.g., OWPAN). Fig.10 It is shown that an internal clock 27 is present in the first communication device 16', 16". The optical transmitter / receiver 25 can be synchronized, for example, by a clock signal 27'. Basically, the clock 27 can define the time length of each time slot so that the scheduled transmission / reception of the transmitter / receiver 25 follows the synchronization provided by the clock signal 27'. The internal clock 27 can in turn be synchronized with the clock of the coordinator 12 (second communication device 15) via a synchronization controller 25". The synchronization control 25" can be output by the synchronizer 25, for example. The synchronizer 25 can receive synchronization information (synchronization elements) 81a, 81b from the coordinator 12 (second communication device 15).

[0203] As described above, the synchronizer 25 can count the number of time slots between the current reference time (e.g., the start of a superframe) and the start of a synchronization element (synchronization information) (e.g., the first time slot of the preamble), and compare the calculated number of time slots with the number encoded in the "synchronization time slot field" (timing information). In view of the comparison, the synchronizer 25 can calculate the deviation (offset) and compensate for it by adjusting the timing to the value written in the "synchronization time slot field" (timing information). As described above, the current reference time is generally imagined to be the moment when the superframe starts, that is, the first time slot of the superframe. (The synchronizer 25 can update the time confirmation by controlling the clock 27 by the controller 25").

[0204] It should be noted that synchronization at the first communication device 16', 16" can be performed by evaluating the time distance between the timing information at the time of encoding and the timing reference at the time of measurement (e.g., reference time) from the timing information (e.g., "synchronization time slot field"). In the event that there is a deviation (offset) between the timing information at the time of encoding and the timing reference at the time of measurement (e.g., reference time), the communication device 16', 16" can adjust the internal clock to the timing information at the time of encoding.

[0205] Example of the second communication device 15 (coordinator 12)

[0206] In the above example (for example, in Figure 1and Fig. 9 ) discloses a communication device 15 (coordinator 12) [e.g., a communication device, a base station, a coordinator, a scheduler, etc.] [e.g., for wireless communication, such as optical communication or RF communication]

[0207] wherein the communication device is configured to transmit and / or receive [e.g. in a superframe] a plurality of packets using a schedule [e.g. defined by (individual) allocation of time slots (or slices, which may include multiple time slots) in a superframe to different communication devices (e.g. designated as "GTS") and / or by allocation of time slots (or slices) to random transmissions (e.g. designated as "RTS")] relative to a reference time [e.g. the start of a superframe; e.g. the first time slot of a superframe, the reference may be periodic, but in the alternative it may change; although the reference time may be updated for a new superframe];

[0208] wherein the communication device is configured to transmit synchronization information [e.g., with variable timing relative to a reference time] [e.g., for different superframes, the synchronization information may be transmitted at different timings (e.g., delayed) relative to the reference time];

[0209] The communication device is configured to include [e.g. encoded in a data field] timing information [e.g., in a synchronization element] that defines [and / or describes] the transmission timing of synchronization information [e.g., the timing of the preamble of a packet including synchronization information] [e.g., information on which time slot of the superframe a frame including synchronization information starts] about [e.g., relative to] a reference time [e.g., about the first time slot of a current superframe].

[0210] The second communication device 15 (or the coordinator 12) may be configured to include in the timing information a time distance [eg, in a time slot] from the transmission of the synchronization information [eg, the timing of the preamble of the packet including the synchronization information] and the reference time.

[0211] The second communication device 15 (or the coordinator 12) may be configured to include timing information, information about the time distance from a reference time to a next timing reference [eg "total superframe time slots"].

[0212] The second communication device 15 (or the coordinator 12) may be configured to provide scheduling information to different communication devices [eg, UEs], thereby allocating an exclusive time slot to each different communication device.

[0213] The second communication device 15 (or the coordinator 12) may be configured to provide different communication devices [e.g. UEs] with allocated exclusive time slots [e.g. a slice comprising a plurality of time slots, e.g. a plurality of consecutive time slots] to the communication devices for transmitting at least some control signaling [the control signaling comprises scheduling information, synchronization information (including timing information)] [the scheduling information may comprise a GTS descriptor element and / or an RTS descriptor element] [a plurality of control signalings may be transmitted in at least one packet; they may be distinguished by various techniques, e.g. by using a different preamble or in any case a different unique sequence for each control signaling] [e.g., in some examples, the transmission of the control signaling may be delayed, e.g. taking into account the necessity of transmission or reception of payload data, e.g., like Figure 2 Control signaling 81b transfers from t0 to t1 in the flow; this may occur, for example, if a requirement imposed by a higher layer application is required].

[0214] The second communication device 15 (or the coordinator 12) may be configured to further transmit at least some event-driven control signaling (e.g., in a different channel and / or in a time slot authorized only for transmitting at least some control signaling and / or in at least one RTS; in some examples, the first communication device 16', 16" may always remain waiting to receive a transmission from the second communication device 15 during an unallocated time slot, and the second communication device 15 may therefore occupy the unallocated time slot to transmit at least some event-driven control signaling without having to schedule those event-driven control signaling) [in Figure 2 In the example, the control signaling may be 81b delayed (moved to a later time), but in some examples this does not necessarily require a schedule to be defined and provided to other different communication devices, since the new time slot now occupied by the control signaling 81b is not allocated to any other communication device 15, 16', 16"][The control signaling may include scheduling information, synchronization information (including timing information)][The scheduling information may include GTS descriptor elements and / or RTS descriptor elements][Multiple control signalings may be transmitted in at least one packet; they may be distinguished by various techniques, such as by using a different preamble or in any case a different unique sequence for each control signaling][For example, in some examples, the transmission of event-driven control signaling may be delayed, for example due to the necessity of: transmission or reception of payload data, such as Figure 2 Control signaling 81b transfers from t0 to t1 in the flow; this may occur, for example, if a requirement imposed by a higher layer application is required].

[0215] The second communication device 15 or the coordinator 12 can be configured to delay the transmission of control signaling (81b) [whether scheduled or even driven] [e.g. from t0 to t1] in the event that a higher layer application requires the transmission [e.g. a payload frame from or to a UE, a different communication device] [e.g. the communication device can therefore delay the transmission of control signaling 81b, for example towards the transmission and / or reception of the first next slice (group of consecutive time slots) which is idle (e.g. not allocated to any other different communication device and / or not used at all)].

[0216] The second communication device 15 or the coordinator 12 may cause the control signaling to include [eg have encoded therein] scheduling information for subsequent transmissions (eg for subsequent superframes).

[0217] The second communication device 15 or the coordinator 12 may cause the control signaling to include [eg have encoded therein] synchronization information for subsequent transmissions (eg for subsequent superframes).

[0218] The second communication device 15 or the coordinator 12 may cause the control signaling to include [eg have encoded therein] the announcement information [eg therein is encoded information human readable information, eg encoded in a UTF-8 string, ASCII code, etc.].

[0219] The second communication device 15 or the coordinator 12 may cause the control signalling to include [eg have encoded therein] random access timing information [eg is or comprises an RTS descriptor element], providing information of which time slots are grant-free [eg relative to a reference time].

[0220] The second communication device 15 or the coordinator 12 may cause the control signalling to include [eg encoded therein] granted access timing information [eg is or comprises a GTS descriptor element], providing information [eg about a reference time] which are all grant-free time slots.

[0221] The second communication device 15 or the coordinator 12 may be configured to define scheduling information [eg for future transmissions, eg after a future time reference] by taking traffic into account.

[0222] The second communication device 15 or the coordinator 12 may define the scheduling information [eg for future transmissions, eg after a future time reference] in the following manner:

[0223] In case of relatively high traffic congestion, reducing the number of time slots used for transmission of control signaling and / or increasing the number of granted time slots allocated to at least one of the different communication devices; and / or

[0224] In the case of relatively low traffic congestion, the number of time slots used for transmission of control signaling is increased and / or the number of granted time slots allocated to at least one of the different communication devices is reduced.

[0225] The second communication device 15 (or coordinator 12), wherein the urgency of transmission and / or reception is ranked according to the urgency level, wherein the communication device is configured to

[0226] In case of a relatively high level of transmission and / or reception, reducing the number of time slots used for transmission of control signaling and / or increasing the number of granted time slots allocated to at least one of the different communication devices; and / or

[0227] In case of a relatively low level of transmission and / or reception, the number of time slots used for transmission of control signaling is increased and / or the number of granted time slots allocated to at least one of the different communication devices is reduced.

[0228] The second communication device 15 or the coordinator 12 may be configured to define a schedule by restoring the time slots used for transmission of control signaling [partially or fully] if a threshold condition is reached [eg when it is no longer possible to avoid transmission of control signaling].

[0229] The second communication device 15 or the coordinator 12 may also include multiple front ends [eg, repeaters] configured to simultaneously transmit and / or receive different packets through different front ends.

[0230] The second communication device 15 or the coordinator 12 may be configured to selectively transmit synchronization information [or more generally different control signaling] for different front ends simultaneously in different time slots [e.g. the scheduling may vary for different front ends and the above situation may apply to each front end while other front ends may also encounter different situations].

[0231] The second communication device 15 or the coordinator 12 may include or be connected to a higher layer application, which uses information about the characteristics of the real-time application data flow (e.g., via an interface) from the higher layer application. [The information about the characteristics of the real-time application data flow may include one or more of the following: periodicity of the application data flow, maximum allowed delay, maximum allowed delay variation, size of datagrams, maximum allowed datagram loss rate].

[0232] The second communication device 15 or the coordinator 12 can be configured to use the information about the characteristics of the real-time application data flow, for example in such a way that if the information about the characteristics of the real-time application data flow requires a certain maximum waiting time for the transmission and / or reception of a specific transmission (e.g., from and / or to the UE), time slots that are not scheduled for a specific different communication device (e.g., UE) are granted to a different communication device (e.g., by fast dynamic rescheduling) and / or other transmissions from the communication device (e.g., control signaling) are moved to subsequent time slots [this may occur, for example, if a high-layer application specifies some payload transmissions as having a high level of urgency].

[0233] In the above example (for example, in Figure 1 and Fig. 9 ) shows a communication method [e.g., in downlink, from a communication device, a base station, a coordinator, a scheduler, etc. to a user equipment, a mobile device, etc.] [e.g., for wireless communication, such as optical communication or RF communication], comprising: using a schedule [e.g., defined by allocating time slots (or slices, which may include multiple time slots) in a superframe (individually) to different communication devices (e.g., designated as "GTS") and / or defined by allocating time slots (or slices) to random transmissions (e.g., designated as "RTS")] related to a reference time [e.g., the beginning of a superframe; for example, the first time slot of a superframe, the reference may be periodic, but alternatively it may change; although the reference time may be updated for a new superframe] to transmit and / or receive [e.g., in a superframe] a plurality of packets;

[0234] The method also includes transmitting synchronization information [e.g., having variable timing relative to a reference time] [e.g., for different superframes, the synchronization information can be transmitted with different timings (e.g., delays) relative to the reference time]; wherein transmitting the synchronization information includes including [e.g., encoding in a data field] timing information [e.g., information on which time slot of the superframe the frame including the synchronization information starts] into the synchronization information [e.g., in a synchronization element], defining [and / or describing] the timing of the transmission of the synchronization information relative to [e.g., relative to] a reference time [e.g., relative to the first time slot of the current superframe] [e.g., the timing of the preamble of the packet including the synchronization information].

[0235] Also disclosed is a non-transitory storage unit storing instructions that, when executed by a processor, cause the processor to:

[0236] using a schedule [e.g., defined by (individual) allocation of time slots (or slices, which may include multiple time slots) in a superframe to different communication devices (e.g., designated as "GTS") and / or defined by allocation of time slots (or slices) to random transmissions (e.g., designated as "RTS")] relative to a reference time [e.g., the start of a superframe; e.g., the first time slot of a superframe, the reference may be periodic, but alternatively it may change; although the reference time may be updated for a new superframe];

[0237] controlling the transmission of synchronization information [e.g. with variable timing with respect to a reference time] [e.g. for different superframes, the synchronization information may be transmitted with different timing (e.g. delayed) with respect to a reference time];

[0238] The synchronization information comprises including [e.g. encoding in a data field] timing information [e.g. into a synchronization element], defining [and / or describing] a transmission timing of the synchronization information [e.g. relative to] a reference time [e.g., regarding the first time slot of the current superframe] [e.g., the timing of a preamble of a packet comprising the synchronization information ... synchronization time slot] of the synchronization information [e.g., relative to] a reference time [e.g., regarding the first time slot of the current superframe] [e.g., the timing of a synchronization time slot] of the synchronization information.

[0239] Aspects of the first devices 16' and 16"

[0240] In the above example, a first communication device 16′ or 16″ [e.g., user equipment UE, mobile device, etc.] [e.g., for wireless communication, such as optical communication or RF communication] is disclosed, which is configured to receive [e.g., in downlink and / or uplink] synchronization information [e.g., with variable timing with respect to a reference time] [e.g., for different superframes, the synchronization information may be transmitted in different timings (e.g., delays) with respect to the reference time];

[0241] wherein the first communication device (16', 16") is configured to transmit and / or receive [e.g. in a superframe] a plurality of packets [e.g., the transmission and / or reception is synchronized to the reference time] using a schedule [e.g. defined by (individual) allocation of time slots (or slices, which may include a plurality of time slots) in a superframe to different communication devices (e.g., designated as "GTS") and / or by allocation of time slots (or slices) to random transmissions (e.g., designated as "RTS")] related to a reference time [e.g., the start of a superframe; e.g., the first time slot of a superframe, the reference may be periodic, but alternatively it may change; although the reference time may be updated for a new superframe];

[0242] Wherein the first communication device (16', 16") is configured to evaluate timing information [e.g., "synchronization time slot" information; for example, information on which time slot of a superframe the frame containing the synchronization information starts], which is included [e.g., encoded] in the synchronization information and which defines [and / or describes] the timing of the transmission of the synchronization information [e.g., the timing of the preamble of the packet including the synchronization information] with respect to [e.g., relative to] a reference time [e.g., relative to the first time slot of the current superframe], in order to perform synchronization [e.g., in order to synchronize its clock with the received synchronization information, e.g., by reducing the offset between its (local) clock and the time indicated by the timing information within the synchronization information] [e.g., the communication device can thereby obtain which moment is the reference time confirmation, and thereby subsequently use the updated timing related to the reference time to transmit and / or receive the next frame].

[0243] The first communication device 16' or 16" can be configured to evaluate the time distance from the transmission of the synchronization information [e.g., in a time slot] [e.g., the timing of the preamble of the packet including the synchronization information] and the timing reference [e.g., by subtracting the time distance from the transmission of the synchronization information to obtain which moment is the reference time confirmation, thereby subsequently transmitting and / or receiving the next frame using an updated time related to the reference time] based on the timing information.

[0244] The first communication device 16 ′ or 16 ″ may be configured to evaluate information about the time distance from a timing reference to a next timing reference [eg “total superframe time slots”] based on the timing information.

[0245] A first communication device (e.g., 16') may be configured to receive scheduling information allocating exclusive time slots for it, with different exclusive time slots being allocated to different first communication devices (e.g., 16"), such that the first communication device 16' transmits in the time slots allocated to it and avoids transmitting in the time slots allocated to different first communication devices 16" [and / or some unused time slots, which may be used, for example, by a master device, e.g., in an emergency].

[0246] The first communication device 16' or 16" may be configured to receive scheduling information allocating an exclusive time slot [e.g., a slice comprising a plurality of time slots, e.g., a plurality of consecutive time slots] to the second communication device (e.g., master communication device) 15 [or a communication device, a base station, or a coordinator, or a scheduler] for transmission of at least a portion of control signaling [e.g., in a downlink], such that the first communication device receives control signaling in the time slot allocated for transmission of at least the control signaling [e.g., in a downlink] [the control signaling may include scheduling information, synchronization information (including timing information)] [the scheduling information may include a GTS descriptor element and / or an RTS descriptor element] [a plurality of control signalings may be transmitted in at least one packet; they may be distinguished by various techniques, e.g., by using a different preamble or in any case a different unique sequence for each control signaling] [e.g., in some examples, the transmission of the control signaling may be delayed, e.g., taking into account the necessity of transmission or reception of payload data, e.g., like Figure 2 Control signaling 81b transfers from t0 to t1 in the flow; this may occur, for example, if a requirement imposed by a higher layer application is required].

[0247] The first communication device 16' or 16" can be configured to receive at least some event-driven control signaling (for example, in a different channel and / or in a different time slot, only authorized to receive at least some control signaling, and / or in at least one RTS; in some examples, during the unallocated time slot, the first communication device can remain waiting to receive a transmission from the master communication device 15 (or communication device, base station, or coordinator, or scheduler or second communication device), and the master communication device 15 (or communication device, base station, or coordinator, or scheduler or second communication device) can therefore occupy the unallocated time slot to transmit at least some event-driven control signaling without having to schedule those event-driven control signaling) [in Figure 2 In the example of , the control signaling 81b may be delayed (shifted to a later time), but in some examples this does not necessarily require a schedule to be defined and provided to the other different communication devices, since the new time slot now occupied by the control signaling 81b is not allocated to any of the other communication devices 15, 16', 16", etc.] [The control signaling may include scheduling information, synchronization information (including timing information)] [The scheduling information may include GTS descriptor elements and / or RTS descriptor elements] [Multiple control signalings may be transmitted in at least one packet; they may be distinguished by various techniques, such as by using a different preamble or in any case a different unique sequence for each control signaling] [For example, in some examples, the transmission of the control signaling may be delayed, for example taking into account the necessity of transmission or reception of payload data, such as Figure 2The same is true for control signaling 81b in which the control signaling 81b is transferred from t0 to t1; this may occur, for example, in situations where a requirement imposed by a higher layer application is required].

[0248] The first communication device 16' or 16" may cause the control signaling to include [eg have encoded therein] scheduling information for subsequent transmissions.

[0249] The first communication device 16' or 16", wherein the control signaling includes [eg has encoded therein] synchronization information for subsequent transmission.

[0250] The first communication device 16' or 16" may cause the control signaling to include [e.g. have encoded therein] the announcement information [e.g. there is encoded information human readable information, e.g. encoded in UTF-8 string, ASCII code, etc.]

[0251] The second communication device 16' or 16" may cause the control signalling to include [eg have encoded therein] random access timing information [eg be or include an RTS descriptor element] providing information about grant-free time slots [eg about a timing reference or reference time].

[0252] The first communication device 16' or 16", wherein the control signaling comprises [eg has encoded therein] grant access timing information [eg is or comprises a GTS descriptor element], providing information about grant-free time slots [eg about a reference time].

[0253] The first communication device 16' or 16" may be such that if information about the characteristics of the real-time application data flow defined by a higher-level application requires a certain maximum waiting time for the transmission and / or reception of a certain transmission, a time slot not scheduled for the first communication device is granted to a different communication device (e.g., by fast dynamic rescheduling) [other transmissions from the master communication device 15 (e.g., control signaling) may be shifted to subsequent time slots] [for example, this may occur in a situation where the higher-level application specifies some payload transmissions as having a high level of urgency].

[0254] In the examples disclosed above, the communication method [e.g., at a user equipment UE, a mobile device, etc.] [e.g., for wireless communication, such as optical communication or RF communication] includes

[0255] receiving synchronization information [e.g., with variable timing relative to a reference time] [e.g., the synchronization information may be transmitted at different timings (e.g., delays) relative to the reference time for different superframes];

[0256] transmitting and / or receiving a plurality of packets [e.g., in a superframe] using a schedule [e.g., defined by (individual) allocation of time slots (or slices, which may include a plurality of time slots) in a superframe to different communication devices (e.g., designated as "GTS") and / or defined by allocation of time slots (or slices) to random transmissions (e.g., designated as "RTS")] relative to a reference time [e.g., the start of a superframe; e.g., the first time slot of a superframe, the reference may be periodic, but alternatively it may change; although the reference time may be updated for a new superframe] [e.g., the transmission and / or reception is synchronized with the reference time];

[0257] Evaluate timing information [e.g., "synchronization time slot" information; for example, information about in which time slot of a superframe a frame including the synchronization information starts], which is included [e.g., encoded] in the synchronization information and defines [and / or describes] the timing of the transmission of the synchronization information [e.g., relative to] a reference time [e.g., relative to the first time slot of the current superframe] [e.g., the timing of the preamble of a packet including the synchronization information], so as to perform synchronization [e.g., by reducing the offset between its (local) clock and the time indicated by the timing information within the synchronization information, for example, so as to synchronize its clock to the received synchronization information] [e.g., the communication device can thereby obtain which moment is the reference time confirmation, and thereby subsequently use the updated timing related to the reference time to transmit and / or receive the next frame].

[0258] Also described is a non-transitory storage unit storing instructions that, when executed by a processor, causes the processor to

[0259] controlling reception of synchronization information [e.g. with variable timing relative to a reference time] [e.g. for different superframes, the synchronization information may be transmitted with different timing relative to a reference time (e.g. delayed)];

[0260] controlling transmission and / or reception of a plurality of packets [e.g., in a superframe] using a schedule [e.g., defined by (individual) allocation of time slots (or slices, which may include a plurality of time slots) in a superframe to different communication devices (e.g., designated as "GTS") and / or defined by allocation of time slots (or slices) to random transmissions (e.g., designated as "RTS")] relative to a reference time [e.g., the start of a superframe; e.g., the first time slot of a superframe, the reference may be periodic, but alternatively it may change; although the reference time may be updated for a new superframe];

[0261] Evaluate timing information [e.g., "synchronization time slot" information; for example, information about in which time slot of a superframe a frame including the synchronization information starts], which is included [e.g., encoded] in the synchronization information and defines [and / or describes] the timing of the transmission of the synchronization information [e.g., relative to] a reference time [e.g., relative to the first time slot of the current superframe] [e.g., the timing of the preamble of a packet including the synchronization information], so as to perform synchronization [e.g., by reducing the offset between its (local) clock and the time indicated by the timing information within the synchronization information, for example, so as to synchronize its clock to the received synchronization information] [e.g., the communication device can thereby obtain which moment is the reference time confirmation, and thereby subsequently use the updated timing related to the reference time to transmit and / or receive the next frame].

[0262] Additionally, further examples are defined by the appended claims (examples are also in the claims).It should be noted that any examples defined by the claims may be supplemented by any of the details (features and functions) described in the following sections.

[0263] Furthermore, the examples described in the following sections may be used alone and may also be supplemented by any features in another section or by any features included in the claims.

[0264] In addition, it should be noted that the various aspects described herein can be used alone or in combination. Therefore, details can be added to each of the various aspects without adding details to another aspect of the aspects.

[0265] It should be noted that the present disclosure explicitly or implicitly describes features of mobile communication devices and receivers and mobile communication systems. Therefore, any features described herein can be used in the context of mobile communication devices and in the context of mobile communication systems (e.g., including satellites, mobile communication networks, etc.).

[0266] In addition, the features and functions related to the method disclosed herein may also be used in the device. In addition, any features and functions disclosed herein about the device may also be used in the corresponding method. In other words, the method disclosed herein may be supplemented by any features and functions described about the device.

[0267] Furthermore, any features and functions described herein may be implemented in hardware or software, or using a combination of hardware and software, as described.

[0268] According to some implementation requirements, the examples can be implemented in hardware. The implementation can be performed using a digital storage medium, such as a floppy disk, a digital versatile disk (DVD), a Blu-ray disk, a compact disk (CD), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory, on which electronically readable control signaling is stored, which cooperates (or can cooperate) with a programmable computer system to perform the corresponding method. Therefore, the digital storage medium can be computer-readable.

[0269] Generally speaking, the examples can be implemented as a computer program product with program instructions, which, when the computer program product runs on a computer, are operative to perform one of the methods. The program instructions may, for example, be stored on a machine-readable medium.

[0270] Other examples include a computer program for performing one of the methods described herein, stored on a machine readable carrier. In other words, an example of a method is, therefore, a computer program having program instructions, for performing one of the methods described herein, when the computer program runs on a computer.

[0271] A further example of the method is, therefore, a data carrier medium (or a digital storage medium, or a computer-readable medium) comprising, recorded thereon, the computer program for performing one of the methods described herein. The data carrier medium, the digital storage medium or the recorded medium is tangible and / or non-transitory, as opposed to an intangible and transient signal.

[0272] A further example comprises a processing unit, for example a computer or a programmable logic device, performing one of the methods described herein.

[0273] A further example comprises a computer having installed thereon the computer program for performing one of the methods described herein.

[0274] Yet another example comprises an apparatus or system for transferring (for example, electronically or optically) a computer program for performing one of the methods described herein to a receiver. The receiver may be, for example, a computer, a mobile device, a storage device, etc. The apparatus or system may, for example, comprise a file server for transferring the computer program to the receiver.

[0275] In some examples, a programmable logic device (e.g., a field programmable gate array) can be used to perform some or all of the functions of the methods described herein. In some examples, a field programmable gate array can collaborate with a microprocessor to perform one of the methods described herein. In general, these methods can be performed by any appropriate hardware device.

[0276] The above examples are illustrative of the above principles. It should be understood that modifications and variations of the arrangements and details described herein will be apparent. Therefore, it is intended to be limited by the scope of the appended patent claims, rather than by the specific details presented by the description and explanation of the examples herein.

[0277] The claims add embodiments and / or alternatives of the invention (for example in square brackets or in parentheses and / or in alternatives or in examples).

Claims

1. A communication device (15), in, The communication device (15) is configured to transmit and / or receive a plurality of packets using a schedule associated with a reference time; wherein the communication device (15) is configured to transmit synchronization information (81a, 81b); Therein, the communication device (15) is configured to include timing information defining the timing of the transmission of the synchronization information (81a, 81b) with respect to the reference time in the synchronization information (81a, 81b). 2 . The communication device according to claim 1 , configured to include a time distance from the transmission of the synchronization information and the reference time in the timing information.

3. The communication device according to any one of the preceding claims, configured to include in the timing information information information about the time distance from the reference time to a next timing reference.

4. The communication device according to any one of the preceding claims, configured to provide scheduling information to the different communication devices, allocating an exclusive time slot to each of the different communication devices.

5. A communication device according to any preceding claim, configured to provide scheduling information to said different communication devices, allocating exclusive time slots to said communication devices for said transmission of at least some control signalling.

6. A communication device according to any preceding claim, configured to further transmit at least some event driven control signalling.

7. The communication device according to claim 5 or 6, wherein the control signaling includes at least the synchronization information.

8. The communication device according to any one of claims 5-7, configured to delay or anticipate the transmission of control signaling in case a higher layer application requires the transmission and / or reception of the transmission.

9. The communication device according to any one of claims 5-8 is configured to check whether at least some time slots are idle according to the scheduling when the high-level application requires the transmission and / or reception of payload data, and thus delay or anticipate the transmission of the control signaling in the idle time slots in the same superframe, otherwise wait for the next superframe.

10. The communication device according to any one of claims 5-9, wherein the control signaling includes scheduling information for the subsequent transmission.

11. The communication device according to any one of claims 5 to 10, wherein the control signaling includes the synchronization information for the subsequent transmission.

12. The communication device according to any one of claims 5 to 11, wherein the control signaling comprises announcement information.

13. The communication device according to any one of claims 5 to 12, wherein the control signaling comprises random access timing information providing information about grant-free time slots.

14. The communication device according to any one of claims 5 to 13, wherein the control signaling comprises grant access timing information providing information about grant-free time slots.

15. The communication device according to any one of claims 5 to 14, configured to define the scheduling information by taking traffic into consideration.

16. The communication device according to claim 15, wherein the scheduling information is defined in the following manner: In case of relatively high traffic congestion, reducing the number of time slots used for said transmission of control signalling and / or increasing the number of granted time slots allocated to at least one of said different communication devices; and / or In case of relatively low traffic congestion, the number of time slots used for said transmission of control signaling is increased and / or the number of granted time slots allocated to at least one of said different communication devices is reduced.

17. The communication device according to claim 15 or 16, wherein the urgency of the transmission and / or reception is ranked according to the urgency level, wherein the communication device is configured to In case of a relatively high level of transmission and / or reception, reducing the number of time slots used for said transmission of control signalling and / or increasing the number of granted time slots allocated to at least one of said different communication devices; and / or In case of a relatively low level transmission and / or reception, the number of time slots used for said transmission of control signaling is increased and / or the number of granted time slots allocated to at least one of said different communication devices is reduced.

18. The communication device according to claim 15 or 16 or 17, configured to define the schedule by resuming the time slot used for the transmission of the control signaling if a threshold condition is met.

19. The communication device according to any one of the preceding claims, further comprising a plurality of front ends, the plurality of front ends being configured to transmit and / or receive different packets simultaneously through the different front ends.

20. The communication device of claim 19, configured to selectively transmit synchronization information simultaneously for different front ends in different time slots.

21. A communication device according to any preceding claim, comprising or connected to a higher layer application, the communication device using information about characteristics of a real-time application data stream from the higher layer application.

22. The communication device according to claim 21, wherein: The information about the characteristics of the real-time application data flow includes one or more of the following: periodicity of the application data flow, maximum allowed delay, maximum allowed delay variation, and maximum allowed datagram loss rate.

23. A communication device according to claim 21 or 22, wherein the communication device is configured to use the information about the characteristics of the real-time application data stream, for example in such a way that if the information about the characteristics of the real-time application data stream requires a specific maximum waiting time for the transmission and / or reception of a specific transmission, a time slot not scheduled for a specific different communication device is granted to the different communication device, and / or other transmissions from the communication device are transferred to subsequent time slots.

24. The communication device according to any one of the preceding claims, configured to transmit and / or receive the plurality of packets as wireless signals, and to transmit the synchronization information in wireless signals.

25. The communication device according to any one of the preceding claims, configured to transmit and / or receive the plurality of packets as optical signals and to transmit the synchronization information in optical signals.

26. A communication method, comprising: transmitting and / or receiving a plurality of packets using a schedule relative to a reference time; The method also includes transmitting synchronization information; Wherein transmitting synchronization information comprises including into said synchronization information timing information defining a timing of said transmission of said synchronization information with respect to a reference time.

27. A non-transitory storage unit storing instructions which, when executed by a processor, cause the processor to: controlling transmission and / or reception of a plurality of packets using a schedule relative to a reference time; Control the transmission of synchronization information; wherein the synchronization information comprises including timing information defining the timing of transmission of the synchronization information with respect to a reference time into the synchronization information.

28. A communication device (16', 16") in, The communication device (16', 16") is configured to receive synchronization information (81a, 81b); wherein the communication device (16', 16") is configured to transmit and / or receive a plurality of packets using a schedule associated with a reference time; Therein, the communication device (16', 16") is configured to evaluate timing information in order to perform synchronization, the timing information being included in synchronization information (81a, 81b) and defining the timing of the transmission of the synchronization information (81a, 81b) with respect to the reference time.

29. The communication device according to claim 28, configured to evaluate information about the time distance from the timing reference to the next timing reference based on the timing information.

30. The communication device according to claim 28 or 29, configured to resynchronize by comparing the time position of the measured reference time with the timing information.

31. A communication device according to any of claims 29-30, configured to read the timing information to determine a time deviation with respect to the timing information, and thereby to modify the time confirmation using the time deviation.

32. The communication device according to claim 29 or 30 or 31 is configured to count the number of time slots between the current reference time and the start of the synchronization information, and compare the counted number of time slots with the number encoded in the timing information, thereby calculating the offset and compensating for the offset by adjusting its timing to the timing information.

33. A communication device according to any one of claims 28-32, configured to receive scheduling information for allocating an exclusive time slot to the communication device and allocating different exclusive time slots to different communication devices, so that the communication device transmits in the time slot allocated to the communication device and avoids transmitting in the time slot allocated to the different communication devices.

34. The communication device according to any one of claims 28-33 is configured to receive scheduling information allocating an exclusive time slot to the primary communication device for the transmission of control signaling, so that the communication device receives the control signaling in the time slot allocated to the transmission of at least the control signaling.

35. A communication device according to any one of claims 28-34, configured to receive at least some event-driven control signaling during the unallocated time slot, and the master communication device can therefore occupy the unallocated time slot to transmit at least some event-driven control signaling without having to schedule those event-driven control signaling.

36. The communication device according to claim 34 or 35, wherein the control signaling includes scheduling information for subsequent transmissions.

37. The communication device according to any one of claims 34-36, wherein the control signaling includes the synchronization information for the subsequent transmission.

38. The communication device according to any one of claims 34 to 37, wherein the control signaling comprises announcement information.

39. The communication device according to any one of claims 34-38, wherein the control signaling includes random access timing information providing information about grant-free time slots.

40. The communication device according to any one of claims 34-39, wherein the control signaling includes grant access timing information providing information about grant-free time slots.

41. A communication device according to any one of claims 34-40, configured to include a high-level application (902) or to be connected to a high-level application (902), wherein the communication device is configured to receive payload data from the high-level application (902) and transmit the payload data according to the schedule, and / or wherein the communication device is configured to transmit the payload data to the received high-level application (902) according to the schedule.

42. The communication device according to any one of claims 28 to 41, wherein: If information about the characteristics of the real-time application data flow defined by the higher layer application requires a certain maximum latency for transmission and / or reception of a certain transmission, a time slot not scheduled for said communication device is granted to said different communication device.

43. The communication device according to any one of claims 28 to 42, configured to evaluate, from the timing information, a time distance between the timing information when encoding and the timing reference when measuring.

44. The communication device according to any one of claims 28 to 43, configured to adjust the internal clock to the timing information during encoding when a deviation occurs between the timing information during encoding and the timing reference during measurement.

45. The communication device according to claims 28-44, configured to transmit and / or receive the plurality of packets as wireless signals, and to receive the synchronization information in wireless signals.

46. ​​The communication device according to claims 28-44, configured to transmit and / or receive the plurality of packets as optical signals, and to receive the synchronization information in an optical signal.

47. A communication method comprising Receive synchronization information; transmitting and / or receiving a plurality of packets using a schedule relative to a reference time; Timing information is evaluated in order to perform synchronization, said timing information being included in the synchronization information and defining the timing of said transmission of said synchronization information with respect to said reference time.

48. A non-transitory storage unit storing instructions, which, when executed by a processor, causes the processor Control the reception of synchronization information; controlling transmission and / or reception of a plurality of packets using a schedule relative to a reference time; Timing information is evaluated in order to perform synchronization, said timing information being comprised in the synchronization information and defining the timing of said transmission of said synchronization information with respect to a reference time.

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