Arrangement with a number of units that can communicate with each other via a wireless connection system and a method for use with such a system

• US 7,362,740 B2
• Filed: 08/29/2001
• Issued: 04/22/2008
• Est. Priority Date: 09/12/2000
• Status: Expired due to Fees

• Current Assignee: Callahan Cellular LLC (Intellectual Ventures LLC), Kvaser Consultant Aktiebolag
• Original Assignee: TimeGalactic AB (Scimitar)
• Inventors: Fredriksson, Lars-Berno
• Primary Examiner(s): LEE, CHI HO A
• Application Number:
  US10/363,166
• Publication Number:
  US 20040023678A1
• Time in Patent Office: 2,428 Days
• Field of Search: None
• US Class Current: 370/345
• CPC Class Codes: G06F 1/14 Time supervision arrangements, e.g. real time clock
• CPC Class Codes: H04J 3/0638 Clock or time synchronisation among nodes; Internode synchronisation synchronization for ring networks H04L12/422; data switching networks with synchronous transmission H04L12/43
• CPC Class Codes: H04J 3/0658 Clock or time synchronisation among packet nodes
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/12 Messaging; Mailboxes; Announcements
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 74/04 Scheduled access hybrid access H04W74/02

Abstract

An arrangement comprises a number of units that can communicate with each other via at least one wireless connection system for the transmission of messages. The connection system works with first and second reception areas. A time slot system is established in a first reception area, in which system the units have access to the transmission media in question in allocated and sequential time intervals, during which the units are activated for their respective transmissions and receptions using time information executed in the time slot system, which time information refers to one or more reference times utilized in the time slot system. The means for effecting the time slot system and the respective unit concerned which is located outside the reception area can receive the said time information signals determining the reference time or reference times, which time information signals are obtained from a master time generation system with the second reception area which is larger or smaller than the first reception area. In this way, the said unit can receive the said time information signal and prepare itself completely or partially for tuning to the said time slot system before it enters into or is covered by the first reception area.

Claims

1. An arrangement with a number of mobile units that can communicate with each other via a wireless connection system for transmission of messages which comprise control information and/or data, wherein the mobile units have access to an actual transmission medium in sequential time intervals, at the intervals where the units are actuated for their respective transmissions and receptions by means of a time slot system, the arrangement comprising:

a time reference system;

an algorithm for time slots for transmission, reception and frequency jumping;

the mobile units are pre-synchronized to a respective reference time area of respective local networks before entering the respective local networks and synchronized across at least two geographically separated local networks;

and at least one of the following;

a) in that the arrangement comprises a network area in which the mobile units exercise their communication in a network,

in that the respective mobile units are adapted to identify and receive information related to a radio protocol including rules for the time slots and selection of frequencies in the time slot system and type information on the time reference system that is valid for the arrangement, in that the arrangement also includes a reference time area, which works with said time reference system,

in that at least one mobile unit is adapted to identify said reference time area and synchronize itself to a reference time by means of said type information,

in that said at least one mobile unit is adapted to set its own internal clock in dependence on the reference time and to cause a time generating function in the communications between the mobile units within the local network area, and

in that the reference time is adapted to be separated or independent from said communications of the mobile units in the local network; and

/or

b) in that first mobile units are included in at least two geographically separated local networks,

in that the respective local network includes reference time area,

in that the respective reference time area is adapted with a time reference system selected from among a number of possible time reference systems,

in that a respective mobile unit of second mobile units comprises or constitutes a mobile unit in a stationary local network or at least one of a mobile unit and a stationary unit in a mobile network,

in that the respective mobile unit of the second mobile units is adapted to identify respective reference time area and receive type information about the time reference system, and

in that at least one of said second mobile units is adapted to have its internal clock at least one of set or actuated by said reference time and is adapted to be separated from or independent of the communications of the mobile units in respective networks.

2. Arrangement according to claim 1, characterized in that the respective unit at its connection procedure to the arrangement is bodily inside or outside said network area and/or said time reference area and is adapted to work with a first stage for connection to the actual radio protocol, a second stage for entrance into or identification of the reference time area, and a third stage in which the time generating function is performed between the internal clocks of the units.

3. Arrangement according to claim 2, characterized in that the unit or the units, the clock or clocks of which is or are, respectively, set or influenced by the reference time, in its or their turn operate or operates as time master or time masters to that unit or those units of the actual units which have not been set or influenced by the reference time.

4. An arrangement according to claim 3, characterized in that the units are mobile and can end up outside the first reception area due to variations and or movements of this and/or movements of the unit, that is in the case of mobile units, in that the first reception area is considerably larger than the second reception area and in that the respective (mobile) units prepare themselves completely or partially before entry or re-entry into the first reception area.

5. An arrangement according to claim 4, characterized in that in the case where the mobile unit'"'"'s current setting gives a sequence of time slots which coincides with the time slot sequence for the mobile unit scheduled in advance by the time slot system, the mobile unit is arranged to permit direct message transmission to or from other unit(s) in the arrangement when it enters into or is covered by the first reception area, and in that in the case where the tuning of the mobile unit gives a sequence of the mobile unit'"'"'s time slots that differs from the sequence scheduled in advance in the arrangement, that is the mobile unit'"'"'s sequence is out of phase with the scheduled sequence, the mobile unit exchanges information with the said devices and from these obtains correction or displacement of its time slot sequence so that it conforms with the scheduled sequence.

6. An arrangement according to claim 5, characterized in that the first reception area is moved via the unit or units which are arranged to be fixed or mobile.

7. An arrangement according to claim 6, characterized in that the said reference time(s) emanate secondarily from master time generation which is arranged within a second reception area located inside the first reception area.

8. An arrangement according to claim 7, characterized in that a mobile unit that is located or ends up outside the first reception area (due to variation and/or movement of the first reception area and/or the mobile unit) obtains the reference time indication in the first reception area upon entry into the first reception area.

9. An arrangement according to claim 8, characterized in that updating and maintenance of accuracy of the reference time(s) of the first reception area are effected by one or more mobile units entering into or being covered by the second reception area at least temporarily for a predetermined minimum interval of time and thereby obtaining for other mobile units in the first reception area updated reference time(s) that is transformed.

10. An arrangement according to claim 9, characterized in that the system works with or comprises a radio system of the Bluetooth type which works with symmetrical slots with predetermined frequency, that the system jumps between a number of frequencies that respective mobile nodes incorporated in the system are pre-synchronized to the system by means of knowledge of an initial time (t), the algorithm for time slots for transmission and reception and for frequency jumping, and that as soon as it has entered into the fixed system the respective mobile node is synchronized only with the fixed network, which in turn is synchronized to the reference time system, that is the requirement that the mobile node is to be directly synchronized to the reference time system no longer applies.

11. An arrangement according to claim 10, characterized in that the mobile node is arranged to synchronize itself into the system as soon as it is able to synchronize itself to the time in the reference time system.

12. An arrangement according to claim 11, characterized in that respective mobile units first obtain or acquire the requisite protocol information before they enter into or are covered by the reception area in question.

13. An arrangement according to claim 12, characterized in that in the case where the reference time area is smaller than the network area, nodes concerned receive the requisite protocol information outside the reference time and network areas, that when it enters into or is covered by the network area the unit lacks the ability to synchronize itself to this, as it is not synchronized to the reference system, but the unit synchronizes itself to the reference time once it has entered into or is covered by the reference time area and when this has occurred the unit is arranged to calculated the correct frequencies and time slots and is able to connect itself to the network using other relevant protocol information and that when it is inside the network area the unit can thereafter leave the time reference area, as it is sufficient for the unit or units that are within the time reference area to be synchronized to the reference time.

14. An arrangement according to claim 13, characterized in that the units connected to the network that are outside the reference time area maintain the synchronization by using the time slots of the units synchronized to the reference time as secondary reference time indicators.

15. An arrangement according to claim 14, characterized in that at least any one unit in the network must enter the reference time area for re-synchronization before the time slots in the system fall outside acceptable tolerance levels.

16. An arrangement according to claim 15, characterized in that the system comprises or is based on advertising boards along one or more roads or sections of road along which vehicles or other mobile units move, that the advertising boards are arranged with radio units, the coverage areas of which are not overlapping, meaning that they can have or utilize the same frequency arrangement and time slots and can work in a synchronous way and that the respective coverage areas have access to the reference time system, which preferably consists of the GPS system.

17. An arrangement according to claim 16, characterized in that the vehicle which moves along the road or section of road is in contact with and is synchronized to the reference system, that when the vehicle passes the advertising boards, the vehicle receives messages from the advertising boards.

18. An arrangement according to claims 16 and 17, characterized in that the contact between the advertising boards and the vehicle is two way and that information from the vehicle is thus able to be transmitted to the advertising boards, that the coverage area for an advertising board consists of a predetermined distance along the road for effective contact with the car for a period of time if the vehicle is travelling in a range from 0 to 100 km/hour.

19. An arrangement according to claim 18, characterized in that the coverage areas of the advertising boards overlap each other and that the advertising boards interact in a shared network, which means that the time slots are divided between them, whereby only one unit needs to be synchronized to the reference time system and other units can synchronize on the time slots in the network.

20. An arrangement according to claim 19, characterized in that the system is arranged with parallel road lanes, where each lane has two sets of traffic lights, one at the entrance and one at the exit, that a sensor is arranged at the entrance and the exit to each lane, which sensor detects the passing of the respective vehicle, the respective lane is provided with a local wired network that is connected to a lane controller unit, to the traffic lights and to a number of radio units that are sequentially overlapped, which lane controller unit is in turn connected to a wired network, which is connected to a charging system via a road toll unit.

21. An arrangement according to claim 20, characterized in that if there is no vehicle/car in a lane, the entrance light shows green and the exit light shows red, that when a vehicle/car passes the sensor the entrance light changes to red, after which the vehicle/car passes the radio units that work in a synchronous way, that while the vehicle/car passes the respective radio units, requisite information is exchanged for the purpose of charging for the road toll, and that thereafter the exit light changes to red and when the vehicle/car has passed the exit sensor, the lane in question returns to its original status.

22. An arrangement according to claim 20 or 21, characterized in that the radio units working in a synchronous way obtain a redundant connection to the passing vehicle/car with good range in the longitudinal direction of the lane, but with a limited range in the transverse direction, where the propagation diagram in question is improved or optimized by the use of directional antennas.

23. An arrangement according to claim 22, characterized in that the radio units are grouped in order to minimize crosstalk and message packet collisions between the lanes, and/or that the time slots are coordinated so that crosstalk or message packet collisions are eliminated.

24. An arrangement according to claim 23, characterized in that the respective local networks (64, 65, 66) operate with a time slot system in which the schedules are phase-displaced in frequency (in a known way) in each time slot and the channel frequency thus obtained in the respective time slots is allocated to a particular category of at least one of customer or staff.

25. An arrangement according to claim 24, characterized in that a first channel frequency is allocated to the local network'"'"'s customers and a second channel frequency is allocated to the local network'"'"'s staff.

26. An arrangement according to claim 25, characterized in that a first channel frequency (71′

) is allocated to a first category of customer and a second channel frequency (72′

) is allocated to a second category of customer.

27. An arrangement according to claim 26, characterized in that the channel frequency in accordance with the utilized signal protocol jumps at random and at the same time in accordance with algorithms incorporated in the protocol.

28. An arrangement according to claim 27, characterized in that the local networks (64, 65, 66) are arranged at petrol stations and that the mobile units are allocated or belong to the stations'"'"' customers.

29. An arrangement according to claim 28, characterized in that the scheduling is distributed and that separation of different categories of at least one of customer or staff is carried out in time and/or frequency, and that the transmission in the radio apparatus (transmitter/receiver) concerned operates with directed transmissions in order that staff or customer apparatus in close proximity to other staff or customer apparatus will not be subject to interference.

30. An arrangement according to claim 29, characterized in that the error-detection function utilizes detection of the signal strength and in certain cases (a multipath situation), also utilizes error-detection code in the signal protocol, changing of the antenna propagation and/or antenna direction.

31. An arrangement according to claim 30, characterized in that, prior to entering into a local network, the respective mobile unit refers to a basic signal protocol system with regard to utilized schedule, jump algorithms, protocol, transmissions, transmission direction, etc, by means of which basic system the mobile unit makes contact with the respective local network for changing to corresponding current parameters that apply in the local network.

32. An arrangement according to claim 31, characterized in that the local network is arranged to operate with a function for approving the entering mobile customers.

33. An arrangement for establishing a common global time-keeping for a system, comprising:

mobile units pre-synchronized to a respective reference time area of respective local networks before entering the respective local networks and synchronized across at least two geographically separated local networks,

wherein each node incorporated in the system is allocated a local time that can either be the same as or related to a global time, that a schedule is drawn up for a number, preferably all, of the nodes in the system,

which schedule has time slots referring to the global time for transmission and reception of messages, and that the time slots are distributed to each node that are allocated the messages that the node is intended to transmit or receive in such a way that receivers and destinations(s) for the majority of all messages are determined only from knowledge of the system'"'"'s schedule, the common global time keeping and the time slot in which the message is sent.

34. An arrangement according to claim 33, characterized in that each receiver determines whether a message is destined for it by the time slot in which the message is sent being allocated to that receiver for the reception of messages.

35. An arrangement according to claim 33 or 34, characterized in that messages that are received in time slots at other times than those covered by allocated time slots for reception are saved with information about the time slot or time of reception in order to re-send the message in the receiver'"'"'s own transmission time slot, if so required.

36. An arrangement according to claim 33, 34 or 35, characterized in that the signal strength of messages that have the correct bit content according to the protocol'"'"'s error-detection mechanisms, but which are received in time slots other than those allocated to the node, are saved with information about the time slot or time of reception and this information is used in order to optimize the system.

37. An arrangement according to any one of claims 33-36, characterized in that redundant information in the messages, for at least one of sender, recipient and message identity, is used to detect errors in the scheduling or implementation of the respective node'"'"'s part of the schedule.

38. An arrangement comprising mobile units incorporated in a network system, characterized in that the mobile units are able to be connected to the network system by means of a time base that is common to the network system, comprising:

mobile units pre-synchronized to a respective reference time area of respective local networks before entering the respective local networks and synchronized across at least two geographically separated local networks,

wherein the time base lacks a geographical relationship to the network'"'"'s radio coverage of the network system and emanates from an independent time generation source,

wherein parts of a utilized network protocol necessary for radio communication between the units and associated time slots and frequencies are related to the time base by means of algorithms, that, for a given time, allows for the relevant frequency and time slot to be calculated.

39. An arrangement according to claim 38, characterized in that a virtual, geographically-independent network thereby exists, where all nodes that are intended to be incorporated are synchronized in advance to the network or the network system.

40. An arrangement according to claim 38 or 39, characterized in that a sub-network that is limited by the radio range of the mobile units incorporated in the sub-network is able to be established without, or with greatly simplified, hand-shaking procedures.

41. An arrangement according to claim 40, characterized in that time messages are to be found on a previously selected frequency.

42. An arrangement according to claim 41, characterized in that the frequency is fixed and that the time message, in addition to comprising the actual time, also contains information or data that identifies the system and that a mobile unit not connected to the system at the time in question is able to synchronize itself to the network on the messages that are due to be sent in order to maintain a global time in the system.

43. An arrangement according to 42, characterized in that the fixed network system in question is situated on a vehicle/car and that fixed and/or mobile nodes are able to be covered by the vehicle/car'"'"'s network.

44. An arrangement with a number of mobile units which can communicate with each other via a wireless connection system for the transmission of messages with control information data (commands) and/or process data where the connection system works with a first reception area and a time slot system comprising:

mobile units pre-synchronized to a respective reference time area of respective local networks before entering the respective local networks and synchronized across at least two geographically separated local networks;

wherein the time slot system, the units have access to the relevant transmission media in allocated and sequential time intervals, in which intervals the units are activated for their transmissions or receptions by means of time information executed in the time slot system, referring to one or more reference times utilized in the time slot system, characterized in that the said reference time(s) emanate secondarily from master time generation that is arranged within a second reception area located inside the first reception area, that a mobile unit that is located or ends up outside the first reception area due to variation and/or movement of the first reception area and/or movement of the unit, obtains reference time indication when the unit is covered by the first reception area or enters into the first reception area, and that updating and maintaining of the accuracy of the first area'"'"'s reference time(s) is effected by one or more mobile units entering, being covered by or being located in the second reception area at least temporarily for a predetermined minimum interval of time, and obtaining for other mobile units in the first reception area updated reference time(s) that is transformed.