Method, device, and system for radio communication at short distances

• US 6,047,177 A
• Filed: 01/23/1997
• Issued: 04/04/2000
• Est. Priority Date: 01/26/1996
• Status: Expired due to Term

• Current Assignee: Hanger Solutions, LLC (IP Investments Group LLC)
• Original Assignee: Telia AB (Government of Norway)
• Inventors: Wickman, Johan
• Primary Examiner(s): LE, THANH C
• Application Number:
  US08/787,173
• Time in Patent Office: 1,167 Days
• Field of Search: 455/422, 455/426, 455/458, 455/446, 455/450, 455/452, 455/451, 455/454, 455/455, 455/550, 455/552, 455/562, 455/62, 455/461, 455/462, 455/466, 348/6, 348/7, 348/13
• US Class Current: 455/422.1
• CPC Class Codes: H04W 84/14 WLL [Wireless Local Loop]; RLL [Radio Local Loop]

Abstract

A method, device and system for radio based short range communication makes possible local network access for capacity-demanding broadband services in a cellular short range system such as DECT. Two separate cellular systems for short range communication are integrated to make a hybrid system, where one of the systems is a DECT system and the other system is a LMDS system. The integration combines DECT and LMDS so that LMDS is used for radio transmission between a DECT-PP and a DECT-RFP via an uplink and a downlink, and for transmission of broadband information in a downlink. The DECT aspect is used for speech, narrow band and medium band data communication, and for transmission of authorization/encryption information so that only authorized subscriber can utilize the information which is transmitted via DECT and LMDS.

Claims

1. A radio-based two way short range communication device that provides local network access for broadband services, comprising:

a first cellular system configured to operate in a first frequency range and provide capacity-demanding broadband services having a predetermined bandwidth; and

a second cellular system which when operated individually communicates digital signals between respective terminals at frequencies lower than said first frequency range of said first cellular system and occupying another bandwidth that is narrower than said predetermined bandwidth of said first cellular system, said second cellular system being integrated with said first cellular system such that when said second cellular system is operated jointly with said first cellular system, said digital signals are two-way communicated in a portion of said predetermined bandwidth in said first frequency range of said first cellular system.

2. The device according to claim 1, wherein:

said first cellular system comprises a LMDS system; and

said second cellular system comprises a DECT-system.

3. The device according to claim 2, wherein said frequencies lower than said first frequency range comprise at least one of a complete fraction and a multiple of a partial LMDS-band in said first frequency range, said partial LMDS-band having a 20 MHZ bandwidth which corresponds to a normal bandwidth of DECT signals in said DECT-system.

4. The device according to claim 2, further comprising:

a DECT repeater configured to relay signals to and from a DECT-PP in capacity demanding environments, and provide communication to a DECT-RFP in a control unit at a higher frequency band than said frequencies lower than said first frequency range.

5. The device according to claim 2, wherein said LMDS system comprises a MAC-protocol mechanism for two-way communicating said broadband services and digitizing said LMDS system by incorporating said DECT system with the LMDS system to effect DECT-based broadband communication.

6. The device according to claim 5, wherein said MAC-protocol mechanism uses a MAC-protocol for providing said broadband services in a downlink and providing MAC-messages in an uplink, said MAC-messages in said uplink including a channel quality indicator and another indicator that suggest a new channel having a channel quality that surpasses a predetermined threshold, one of said MAC-messages in the downlink including a decided new channel indicator.

7. The device according to claim 5, wherein;

said DECT system comprises a DECT-PP at a subscriber unit and a DECT-RFP at a control unit, said DECT system configured to transmit digital information via radio transmission in an uplink from said DECT-PP to said DECT RFP, and configured to transmit broadband information in a downlink from said DECT-RFP to said DECT-PP, at least one of said uplink and said downlink carrying transmission of speech, narrow and medium band data information, and ISDN compatible data;

said DECT system comprising an authorization/encryption mechanism that uses authorization/encryption information transmitted in said downlink so that only an authorized subscriber can use the information which is transmitted via said system DECT and said LMDS system;

said LMDS system configured to use a Media Access Control protocol; and

said DECT system further comprising a repeater, said repeater configured to provide connectivity between said DECT-PP, which is configured to operate as a mobile unit, and other components of said DECT system.

8. The device according to claim 7, wherein said subscriber unit comprises:

an attenuator that attenuates an output signal in said second frequency range;

a frequency converter that transforms said output signal after being attenuated to said first frequency range, said frequency converter comprising a local oscillator configured to produce a LO signal that causes said frequency converter to transform said output signal into at least one of any partial LMDS-band;

an amplifier that amplifies said output signal after being transformed by said frequency converter;

an antenna subsystem comprising at least one of a directive transmit antenna, a directive receive antenna, and a directive transceive antenna, said antenna subsystem configured to transmit said output signal, said antenna subsystem also configured to receive a received signal;

a signal level adjustment mechanism configured to adjust a level of said received signal to within a predetermined range, said signal level adjustment mechanism configured to provide said received signal, after adjustment, to said frequency convertor which converts DECT designated signals to said frequencies lower than said first frequency range and provides portions of said received signal, after adjustment, to a LMDS-receiver; and

a filter that removes non DECT designated signals from said received signal prior to providing said DECT designated signals to said DECT-PP.

9. The device according to claim 8, wherein said at least one directive transmit antenna, said directive receive antenna, and said directive transceive antenna comprise a directional antenna having a main beam in a range of 1-3°

so as to suppress multipath effects.

10. The device according to claim 7, wherein said subscriber unit comprises:

a frequency converter that transforms an uplink signal to a frequency which is at least one of a whole multiple and a complete fraction of a frequency of a selected partial LMDS-band;

a local oscillator connected to said frequency converter and configured to provide to said frequency converter a LO signal;

a multiplier that multiplies said uplink signal at said selected partial LMDS band by a factor N and outputs a multiplied output signal; and

an antenna with high directivity that transmits said multiplied output signal.

11. The device according to claim 10, wherein said antenna comprises a directional antenna having a main beam in the range of 1-3°

so as to suppress multipath effects.

12. A method for providing local network access to broadband services in a radio based short range telecommunication system, comprising the steps of:

integrating a first cellular system with a second cellular system, comprising,

operating said first cellular system in a first frequency range that is wholly or partly intended for capacity demanding broadband communications having a predetermined bandwidth,

providing capacity demanding broadband services in said first cellular system, and

allocating in said second cellular system a lower frequency band than said first frequency range and narrower in bandwidth than said predetermined bandwidth of said first cellular system for surface coverage two-way communication with digital signals; and

communicating said digital signals of said second communication system in said predetermined bandwidth in said first frequency range.

13. The method according to claim 12, wherein said integrating step comprises integrating a LMDS-system as said first cellular system with a DECT-system as said second cellular system.

14. The method according to claim 13, wherein:

said step of operating comprises the steps of,

using a MAC-protocol in said LMDS-system, and

digitizing selected messages communicated in said LMDS-system by employing a DECT format therein; and

said step of communicating comprises effecting DECT-based broadband communication by transmitting said digital signals in a portion of said first frequency range allocated to said LMDS-system.

15. The method according to claim 14, wherein said integration step comprises the steps of:

using the LMDS-system for radio transmission between a DECT-PP and a DECT-RFP via an uplink and a downlink;

transmitting broadband information in said downlink, said information comprising at least one of a speech signal, a narrow band data communication signal, a medium band data communication signal, and authorization/encryption information used for Media Access Control for LMDS; and

using DECT-repeaters so as to enable local terminal mobility of said DECT-PP.

16. The method according to claim 15, wherein said transmitting step comprises transmitting said broadband information for said DECT-system in at least of a complete fraction and a multiple of one of a plurality of 20 MHZ partial LMDS-bands, each of which correspond to a normal DECT-system bandwidth.

17. The method according to claim 16, for executing a multimedia service, comprising the steps of:

calling by a subscriber to a central unit using a DECT message format;

requesting by the subscriber the multimedia service;

selecting by the subscriber a service alternative including a code/designation which is shown in a special non-encrypted menu channel via LMDS;

checking at the central unit for whether the subscriber is authorized, and if so, requesting the subscriber to confirm the service alternative previously designated;

confirming by the subscriber the service alternative;

transmitting at the central unit a code key and a channel information via DECT to the subscriber;

forwarding at the DECT-PP the key and the channel information to a decoder and a LMDS-terminal for decoding a respective channel selection;

transmitting the service alternative in a coded form via LMDS where a code used to encode the service alternative is changeable at certain intervals; and

cutting-off by the subscriber the service alternative by dispatching a control command via DECT.

18. The system according to claim 17, wherein at least one of said first cell and said second cell comprises two distinct cellular systems for short range communication, a first one of said two distinct cellular systems configured to transmit and receive digital signals in a first frequency band, and a second one of said two distinct cellular systems having a second frequency band that is higher in frequency and broader in range than said first frequency band, said second frequency band being wholly or partly intended for capacity demanding broadband communication.

19. The system according to claim 18, wherein said first one of first cellular short range systems comprises a DECT-system, and the other cellular short range system comprises a LMDS-system.

20. A radio-based two way short range communication device that provides local network access for broadband services, comprising:

a first cellular system configured to operate in a first frequency range and provide capacity-demanding broadband services in a predetermined bandwidth;

a second cellular system which when operated individually communicates digital signals between respective terminals at frequencies lower than said first frequency range of said first cellular system and in a bandwidth that is narrower than said predetermined bandwidth;

means for integrating said first cellular system with said second cellular system, comprising,

means for operating said first cellular system in the predetermined bandwidth of said first frequency range that is wholly or partly intended for capacity demanding broadband communications,

means for providing capacity demanding broadband services in said first cellular system, and

means for allocating in said second cellular system a lower frequency band than said first frequency range for surface coverage two-way communication with digital signals; and

means for communicating said digital signals of said second communication system in said first frequency range.