ANSI_SCTE 137-1 2010.pdf

More documents

Recommendations

Info

Although a part of the wander will be common-mode between the two clients, the worse case boundary is to assumethat each client clock will have sufficient variation in loop parameters (bandwidth and damping factor) so thatwander is uncorrelated between the two clients. Vendor implementation and aging of components (varactor gain)may contribute to this effect.To determine the level of ranging wander noise introduced by a DTI server, the critical issue is the degree to which aclient clock can track the server. The model of the client tracking suggests a bandpass filter:1. A low pass measurement filter to capture the capability of the client to filter high frequency server noise.2. A high pass error signal filter to capture the client ability to track the server low frequency delay variations.The overall ranging filter is a composite of these two sections generating a bandpass filter.The jitter filter is bounded by the minimal jitter filtering capability of a client. The maximum bandwidth is 10 Hzand the assume filter is single pole (20 dB/decade).The tracking filter is bounded by the minimum 1 Hz bandwidth allowance and assumes a damping factor of 3 and atype II PLL. This high pass filter will attenuate low frequency components with a 40 dB/decade roll off. Thecombination of these two filters performance can be seen below:Ranging Wander Test Filter0-20-40-60Client Error Emulation FilterMeasure FilterComposite Filter-80-1000.0010.010.1110100Figure A–3 - Ranging Wander Test FilterThe ranging wander qualification filter R(S) is defined to be:R(S)= E(S)M(S)Where E(S) is the high pass tracking filter and M(S) is the low pass jitter filter.E(S)= S 2 /(S 2 +5.934 S+0.9784)M(S)= 1/[1+(1/(2π*10 Hz)S]In the special case where the DOCSIS EQAM and upstream receivers are not collocated, there is an additionalallocation of 300 ps RMS for each root server to address the phase variation over a 35 second maximum ranginginterval. Stated another way, each root server is allowed a 300 ps RMS wander with respect to UTC frequency (withthe mean removed). The DTI servers will be required to be traceable to GPS in both locations to obtain this level ofphase coherency.44
Annex BDTI-MIB (normative)DTI-MIB DEFINITIONS ::= BEGINIMPORTSMODULE-IDENTITY,Integer32,Unsigned32,Counter32,OBJECT-TYPEFROM SNMPv2-SMITruthValue,TEXTUAL-CONVENTION FROM SNMPv2-TCOBJECT-GROUP,MODULE-COMPLIANCE FROM SNMPv2-CONFInetAddressType,InetAddressFROM INET-ADDRESS-MIBifIndexFROM IF-MIBPhysicalIndexFROM ENTITY-MIBEntitySensorValue,EntitySensorDataScale FROM ENTITY-SENSOR-MIBclabProjDocsisFROM CLAB-DEF-MIB;dtiMib MODULE-IDENTITYLAST-UPDATED "200812090000Z" -- December 9, 2008ORGANIZATION "CableLabs Cable Television Laboratories, Inc"CONTACT-INFO"Postal: Cable Television Laboratories, Inc858 Coal Creek CircleLouisville, CO 80027U.S.A.Phone: +1 303-661-9100Fax: +1 303-661-9199E-mail: mibs@cablelabs.com"DESCRIPTION"This MIB module provides the management objects necessaryto configure and manage the DOCSIS Timing Interfacedevices.Copyright 2005-2008 Cable Television Laboratories, Inc.All rights reserved."REVISION "200812090000Z" -- December 9, 2008DESCRIPTION"Revised Version includes ECN DTI-N-08.0698-2and is published as CM-SP-DTI-I05-081209."REVISION "200712060000Z" -- December 6, 2007DESCRIPTION"Revised Version includes ECN M-OSSI-N-07.0562-5and published as I07."REVISION "200708030000Z"DESCRIPTION"Revised Version includes ECN M-OSSI-N-07.0451-3and published as I06."REVISION "200606280000Z" -- June 28, 2006DESCRIPTION"Revised Versionincludes ECN M-OSSI-N-06.0278-4."REVISION "200508050000Z" -- August 5, 2005DESCRIPTION"Initial version of the DTI MIB module.This revision is published as part of the CableLabsM-CMTS specification."::= { clabProjDocsis 7 }45
Page 4 and 5: 7.2.6 DTI Client Test Port ........
Page 6 and 7: This page intentionally left blank.
Page 8 and 9: 1.1.3 Modular Implementation Requir
Page 10 and 11: • The server-to-client-to-server
Page 12 and 13: 3 TERMS AND DEFINITIONSThis specifi
Page 14 and 15: S-CDMATBDTDMTDMAT-ServicesUDPUSUTCS
Page 16 and 17: RJ45 Pin Number Signal Comment4 NC5
Page 18 and 19: 6.2 DTI Timing StructureFigure 6-1
Page 20 and 21: 6.3.1 GPS Frequency ModeIn order to
Page 22 and 23: In the server to client direction,
Page 24 and 25: Bit 7-0:This field contains the sub
Page 26 and 27: The path traceability field start o
Page 28 and 29: Table 6-5 - DTI Client Frame Struct
Page 30 and 31: Bit 8: Data Valid BitThe Client DTI
Page 32: 7 DTI CLIENT AND SERVER OPERATIONTh
Page 35 and 36: 1.0E+041.0E+03DegradedAcceptableMTI
Page 37 and 38: 10 µsecMTIE1 µsec100 nsec0.1 sec
Page 39 and 40: In automatic cable advance mode, th
Page 41 and 42: 7.2.3 DTI Client Mode Transition Di
Page 43 and 44: 7.2.4 Functional RequirementsThe cl
Page 45 and 46: 10.24MHz Phase AlignmentClient10.24
Page 47 and 48: 7.3 DTI Distribution Fallback Strat
Page 49: Annex ARanging Wander Qualification
Page 53 and 54: dtiProtocolServerToDStatedtiProtoco
Page 55 and 56: timing reference.'normalMode'The cl
Page 57 and 58: ::= { dtiProtocolEntry 11 }dtiProto
Page 59 and 60: The Test Mode consist in a sequence
Page 61 and 62: MAX-ACCESS read-onlySTATUS currentD
Page 63 and 64: dtiProtocolClientFsmStatsT7Count OB
Page 65 and 66: MAX-ACCESS read-onlySTATUS currentD
Page 67 and 68: version 4.'gps' indicates support o
Page 69 and 70: -- unconditionally mandatory groups
Page 71 and 72: Appendix IDTI Server Functional Des
Page 73 and 74: Appendix IIDTI Client Functional De
Page 75 and 76: II.2DTI Client Frame ProcessorA blo
Page 77 and 78: delay the integer portion of the se
Page 79 and 80: The output of the DTI server is a M
Page 81 and 82: Appendix IV Symbol Clock Synchroniz
Page 83 and 84: Least Sig. BitLeast Significant Bit
Page 85: VI.2On the other hand, if the MAP i

ANSI_SCTE 137-1 2010.pdf

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?