Acquisition and tracking in communication system with multicarrier telephony transport

• US 6,415,133 B1
• Filed: 09/16/1999
• Issued: 07/02/2002
• Est. Priority Date: 02/06/1995
• Status: Expired due to Fees

• Current Assignee: HTC Corporation
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Geile, Michael J., Brede, Jeffrey, Fort, Michael J., Solum, Jeff
• Primary Examiner(s): CUMMING, WILLIAM D
• Application Number:
  US09/396,964
• Publication Number:
  US 20020098797A1
• Time in Patent Office: 1,020 Days
• Field of Search: 455/6.1, 455/6.2, 455/561, 455/3.05, 725/143
• US Class Current: 455/3.05
• CPC Class Codes: G06F 17/14 Fourier, Walsh or analogous domain transformations , e.g. Laplace, Hilbert, Karhunen-Loeve, transforms for correlation function computation G06F17/156; spectrum analysers G01R23/16
• CPC Class Codes: G06F 17/142 Fast Fourier transforms, e.g. using a Cooley-Tukey type algorithm
• CPC Class Codes: H03M 13/1515 Reed-Solomon codes
• CPC Class Codes: H03M 13/356 Unequal error protection [UEP]
• CPC Class Codes: H04B 10/272 Star-type networks or tree-type networks
• CPC Class Codes: H04H 20/69 Optical systems
• CPC Class Codes: H04H 20/77 using carrier waves
• CPC Class Codes: H04H 20/78 CATV [Community Antenna Television] systems
• CPC Class Codes: H04H 20/79 using downlink of the CATV systems, e.g. audio broadcast via CATV network
• CPC Class Codes: H04H 20/80 having frequencies in two or more frequency bands, e.g. medium wave and VHF
• CPC Class Codes: H04H 60/11 Arrangements for counter-measures when a portion of broadcast information is unavailable
• CPC Class Codes: H04H 60/86 accessed over CATV networks
• CPC Class Codes: H04H 60/96 CATV systems for accessing the Internet H04H60/86
• CPC Class Codes: H04H 60/97 using uplink of the CATV systems
• CPC Class Codes: H04J 14/0298 with sub-carrier multiplexing [SCM]
• CPC Class Codes: H04J 3/14 Monitoring arrangements for SDH/SONET rings H04J3/085
• CPC Class Codes: H04K 1/00 Secret communication
• CPC Class Codes: H04K 3/226 Selection of non-jammed channel for communication spectrum sharing arrangements H04W16/14; selection of wireless resources by user or terminal H04W72/02
• CPC Class Codes: H04K 3/255 based on redundancy of transmitted data, transmission path or transmitting source
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 1/0045 : Arrangements at the receiver end
• CPC Class Codes: H04L 1/0057 : Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0071 : Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/24 : Testing correct operation
• CPC Class Codes: H04L 12/10 : Current supply arrangements
• CPC Class Codes: H04L 12/12 : Arrangements for remote connection or disconnection of substations or of equipment thereof
• CPC Class Codes: H04L 12/2801 : Broadband local area networks
• CPC Class Codes: H04L 12/44 : Star or tree networks
• CPC Class Codes: H04L 2001/0093 : Point-to-multipoint
• CPC Class Codes: H04L 2027/0036 : using a recovered symbol clock
• CPC Class Codes: H04L 2027/0057 : quadrature phase
• CPC Class Codes: H04L 2027/0067 : Phase error detectors
• CPC Class Codes: H04L 25/03866 : using scrambling
• CPC Class Codes: H04L 27/2601 : Multicarrier modulation systems
• CPC Class Codes: H04L 27/2614 : Peak power aspects
• CPC Class Codes: H04L 27/2631 : with polyphase implementation
• CPC Class Codes: H04L 27/2634 : Inverse fast Fourier transform [IFFT] or inverse discrete Fourier transform [IDFT] modulators in combination with other circuits for modulation
• CPC Class Codes: H04L 27/2647 : Arrangements specific to the receiver only equalisation H04L27/01
• CPC Class Codes: H04L 27/2652 : with polyphase implementation
• CPC Class Codes: H04L 27/26524 : Fast Fourier transform [FFT] or discrete Fourier transform [DFT] demodulators in combination with other circuits for demodulation
• CPC Class Codes: H04L 27/2654 : Filtering per subcarrier, e.g. filterbank multicarrier [FBMC]
• CPC Class Codes: H04L 27/2655 : Synchronisation arrangements
• CPC Class Codes: H04L 27/2657 : Carrier synchronisation
• CPC Class Codes: H04L 27/2662 : Symbol synchronisation
• CPC Class Codes: H04L 27/34 : Amplitude- and phase-modulated carrier systems, e.g. quadrature-amplitude modulated carrier systems
• CPC Class Codes: H04L 41/0213 : Standardised network management protocols, e.g. simple network management protocol [SNMP]
• CPC Class Codes: H04L 41/064 : involving time analysis
• CPC Class Codes: H04L 41/0896 : Bandwidth or capacity management, i.e. automatically increasing or decreasing capacities flow or congestion control using dynamic resource allocation, e.g. in-call renegotiation, H04L47/76
• CPC Class Codes: H04L 43/00 : Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/022 : by sampling
• CPC Class Codes: H04L 43/067 : using time frame reporting
• CPC Class Codes: H04L 43/0811 : by checking connectivity
• CPC Class Codes: H04L 43/0817 : by checking functioning
• CPC Class Codes: H04L 43/0823 : Errors, e.g. transmission errors
• CPC Class Codes: H04L 43/0829 : Packet loss
• CPC Class Codes: H04L 43/0847 : Transmission error
• CPC Class Codes: H04L 43/0852 : Delays
• CPC Class Codes: H04L 43/0858 : One way delays
• CPC Class Codes: H04L 43/0864 : Round trip delays
• CPC Class Codes: H04L 43/0882 : Utilisation of link capacity
• CPC Class Codes: H04L 43/16 : Threshold monitoring
• CPC Class Codes: H04L 5/0007 : the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0037 : Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0044 : allocation of payload
• CPC Class Codes: H04L 5/023 : Multiplexing of multicarrier modulation signals multicarrier modulation H04L27/2601
• CPC Class Codes: H04L 5/14 : Two-way operation using the same type of signal, i.e. duplex
• CPC Class Codes: H04L 5/143 : for modulated signals H04L5/1469 takes precedence
• CPC Class Codes: H04L 5/1484 : operating bytewise
• CPC Class Codes: H04M 7/006 : Networks other than PSTN/ISDN providing telephone service, e.g. Voice over Internet Protocol (VoIP) , including next generation networks with a packet-switched transport layer H04L65/00 takes precedence; aspects not specific to the type of network H04M3/00; special services in those networks H04M3/42
• CPC Class Codes: H04M 9/027 : Frequency division multiplex systems
• CPC Class Codes: H04N 21/2221 : being a cable television head-end CATV in broadcast systems H04H20/78
• CPC Class Codes: H04N 21/2383 : Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/2385 : Channel allocation H04N21/266 takes precedence; Bandwidth allocation H04N21/24 takes precedence ; allocation of channels according to the instantaneous demands of the users in time-division multiplex systems H04J3/1682; admission control, resource allocation in open networks H04L12/5692; arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896; negotiating bandwidth in wireless networks H04W28/16
• CPC Class Codes: H04N 21/2402 : Monitoring of the downstream path of the transmission network, e.g. bandwidth available traffic monitoring in data switching networks H04L43/00; monitoring data switching networks utilization H04L43/0876
• CPC Class Codes: H04N 21/4382 : Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/6118 : involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/6137 : involving transmission via a telephone network, e.g. POTS
• CPC Class Codes: H04N 21/6168 : involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 7/17309 : Transmission or handling of upstream communications
• CPC Class Codes: H04N 7/22 : Adaptations for optical transmission
• CPC Class Codes: H04W 24/00 : Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 24/08 : Testing, supervising or monitoring using real traffic
• CPC Class Codes: Y02D 30/50 : in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A method for initializing a service unit in a communication system. The method includes receiving a synchronization signal from a head end at the remote unit. Further, an identifier is received specifying the remote unit. The method further receives an upstream frequency band and control channel designation at the remote unit, wherein the frequency band includes a number of subbands with at least one control channel in each subband. The method tunes to the designated frequency band and a reference signal is transmitted on a selected channel to the head end. The method receives adjustment signals based on the reference signal transmitted to the head end to allow signals transmitted from the remote unit to be orthogonal at the head end to signals from at least one other remote unit. The method adjusts parameters at the remote unit based on the adjustment signals.

Claims

1. In a bidirectional multipoint-to-point multichannel communications system having a single central head end and a plurality of remote units located remotely from the head end and from each other, a method performed by both said one remote unit and said central head end for acquiring one of said remote units into said system, said method comprising:

initializing said one remote unit to communicate with said central head end

sending a sync tone from said head end to all of said remote units;

sending from said head end an identifier specifying said one remote unit;

recognizing said identifier at said one remote unit;

at said remote unit, adjusting the frequency of a tuner in response to the frequency of said sync tone;

sending an upstream frequency-band designation from said head end unit to said one remote unit;

at said remote unit, tuning to said designated frequency band;

transmitting a ranging tone at a predetermined power level from said remote unit to said head end;

at said head end, comparing a power level of said ranging tone to a desired power level, and sending a power-adjust message to said remote unit;

at said remote unit, adjusting a transmission power level in response to said power-adjust message;

at said head end, comparing the phase of said ranging tone to the phase of said sync tone, and sending a phase-adjust message to said remote unit;

at said remote unit, adjusting the phase of said ranging tone toward a desired phase in response to said phase-adjust message;

at said remote unit, sending a locked-in message to said head end when said remote unit has properly adjusted its frequency, phase, and power level.

2. The method of claim 1, wherein said system includes a plurality of command channels interspersed among a number of sets of payload channels, and wherein said messages are communicated between said head end and said one remote unit via said command channels.

3. The method of claim 1, wherein initializing said one remote unit includes:

at said head end, associating a serial number for said one remote unit with a shorter personal identification number (PIN),

sending said PIN to said one remote unit along with said serial number,

at said remote unit, storing said PIN,

at said head end, thereafter including said PIN in messages addressed to said remote unit in place of said identifier, and

at said remote unit, thereafter acting upon only those messages from said head end which include said PIN.

4. The method of claim 1, wherein said one remote unit contains a table of capabilities for said one remote unit, and further comprising:

at said head end, requesting a set of capabilities of said remote unit;

sending said requested capabilities to said head end;

at said head end, storing said requested capabilities; and

thereafter, adjusting commands to said remote unit in response to said capabilities.

5. The method of claim 1, wherein said sync tone comprises a pattern of signals repeated over a predetermined number of data frames, and wherein said one remote unit further adjusts the phase of said ranging tone so as to achieve a predetermined relationship with respect to said pattern.

6. The method of claim 1, wherein initializing side one remote unit includes, at said one remote unit, returning said remote unit so as to receive said sync tone, in response to receiving said identifier from said head end.

7. A method for acquiring a service unit in a communication system, the method comprising:

initializing the service unit to communicate with a head end;

broadcasting a synchronization signal from the head end;

sending from said head end an identifier specifying the service unit;

recognizing the identifier at the service unit;

sending an upstream frequency-band designation from the head end to the service unit;

tuning the service unit to the designated frequency band;

transmitting a ranging signal at a selected power level from the service unit to the head end;

comparing aspects of the ranging signal with selected values;

generating adjustment commands;

adjusting parameters of the service unit based on the adjustments commands from the head end;

sending a locked-in message to the head end; and

wherein comparing aspects of the ranging signal with selected values and generating adjustment commands comprises;

comparing a power level of said ranging signal at the head end to a selected power level;

sending a power-adjust message to the service unit;

adjusting a transmission power level in response to the power-adjust message at the service unit;

comparing the phase of the ranging signal to the phase of the synchronization signal;

sending a phase-adjust message to the service unit; and

adjusting the phase of the ranging signal toward a desired phase in response to said phase-adjust message at the service unit.

8. The method of claim 7, wherein the service unit contains a table of capabilities for the service unit, the method further comprising:

requesting a set of capabilities from the service unit;

sending the requested capabilities to the head end;

storing the requested capabilities at the head end; and

adjusting commands to the service unit in response to the capabilities stored at the head end.

9. The method of claim 7, wherein:

broadcasting the synchronization signal comprises broadcasting a pattern of signals repeated over a predetermined number of data frames; and

transmitting a ranging signal comprises adjusting the phase of the ranging signal so as to achieve a predetermined relationship with respect to the pattern of the synchronization signal.

10. The method of claim 7, and further comprising returning the service unit to receive the synchronization signal prior to transmitting the ranging signal from the service unit.

11. The method of claim 7, wherein initializing the service unit includes associating a serial number for the service unit with a shorter personal identification number (PIN) and sending the PIN to the service unit along with the serial number.