4 Evolution of DOCSIS Pre-DOCSIS DOCSIS 1.0 DOCSIS 1.1 MSO’s needed a service offering for the residential marketConsumer demands dictated the need for something faster than dial-upProprietary and expensiveDOCSIS 1.0MSO’s needed a standardized solution (i.e. cheaper)Consumer demands dictated the need for additional bandwidthCompeting against DSLDOCSIS 1.1MSO’s needed a way to protect their infrastructure and offer differentiated servicesMSO’s needed to expand, start targeting the commercial marketCompeting against DSL, ISDN, and T1Standard defined:security between the CMTS and CM (BPI+)extensive QOS functionality38Mbps x 9Mbps service offering
5 Evolution of DOCSIS (cont) MSO’s needed a way to offer a synchronous serviceVoIP and business servicesConsumer demands dictated the need for more upstream bandwidthGamingConsumer owned servers (Peer-to-Peer)Standard defined:Expanded upstream channel widths to include 6.4MHzExpanded upstream modulation schemes to include 32QAM, 64QAM, and 128QAMS-CDMA38Mbps x 27Mbps service offering
7 Business Drivers for D3.0 More HD Video Services More SD Video Content Competition against FTTH - Deliver 100 MbpsBroadband Internet Services GrowthMigration from Web to Web2.0, Video Streaming, P2P TVIncreased per home consumptionIP Video over DOCSIS(VDOC)High definition Video to multiple devicesPCs, Hybrid STBs, portable devicesMigration from Broadcast to Unicast services (VoD, Startover)Commercial servicesHigh BW data servicesHigh BW Ethernet/L2VPN serviceVideo conferencingDespite the improvements that have occurred as DOCSIS has evolved, maximum data rates to and from cable modems are pretty much topped out. Competition and the desire to provide new services are driving the need for even greater throughput in our DOCSIS networks.We're limited by the fact that the maximum raw data rate to or from cable modems is ultimately constrained by what a single 6 MHz wide channel can carry in the downstream, or what a single 6.4 MHz wide channel can carry in the upstream.Enter DOCSIS 3.0 and something called channel bondingVideo in the Internet is driving data throughput at 41% compound annual growth rate.By 2012, 50% of internet traffic is expected to be videoMore HD Video ServicesGrowth plans to 100+ HD channelsMore SD Video ContentExpansion to nx100 SD chs to compete w/ satellitePersonalized Video ServicesMigration from Broadcast to Unicast servicesVoD, Startover, MyPrimetime, etc
8 Next Generation Connected Home Stored musicIn any roomInternetNext GenMR-DVRInternet videoOn HDTVPhotosFrom PCMulti-MediaClient GatewayMulti-MediaClient GatewayNo New Wires TechnologyOutsideTheHomeNext GenMR-DVRDVR contentOver the InternetNetworkIP ServiceGatewayPhotosFrom PCEthernetInternet videoOn HDTVDVR contentOver the InternetPCStored musicIn any roomMulti-MediaService Gateway
9 Spectral Reclamation Solutions SDV – Switched Digital VideoNode splitsNarrowcast QAM injectionAnalog reclamationUse every channel available1 GHz upgradeMPEG-4SDV Offer more HD and SD content using less total RF spectrum with the same STBOnly transmit the content being actively watchedCould make more QAMs available for DOCSIS and VOD if QAM sharing is implementedNode splits Physically reduce the homes passed per HFC node, thus reduce contention per home for Unicast servicesDecombine more attractiveTriggers additional QAMs and CMTS PortsBroadcast to narrowcast QAM injection Reduce broadcast domains to smaller DOCSIS & video service groupsUltimately a complete Unicast lineup on a per node basisAnalog reclamation for more digital spectrum More QAM channels for Digital Broadcast, VoD, SDV and DOCSISUse every channel available Manage the channel lineup, fill in the gaps, mitigate noise to enable all spectrum1GHz upgrade Make new spectrum for new CPE above 860 MHz
10 Overall Industry Objectives DOCSIS 3.0M-CMTSGoal:More aggregate speedMore per-CM speedEnable New ServicesComponents:Channel BondingIPv6MulticastAESGoal:Increase ScalabilityReduce CostComponents:Low Cost E-QAMCMTS Core ProcessingBetter stat muxing with bigger “pipe”Offer >37 Mbps for single CM
12 DOCSIS 3.0 Features MAC Layer Network Management Network Layer Downstream Channel BondingUpstream Channel BondingNetwork LayerIPv6 supportIP Multicast (IGMPv3/MLDv2, SSM, QoS)SecurityCertificate Revocation ManagementRuntime SW / Config validationEnhanced Traffic Encryption (AES)Certificate ConvergenceEarly Authentication & EncryptionTFTP ProxyNetwork ManagementDiagnostic Log (Flaplist)Extension of Internet Protocol Data Records (IPDR) usageCapacity managementEnhanced signal quality monitoringPhysical LayerSwitchable 5-42 MHz, 5-65 MHz, or 5-85 MHz US bandS-CDMA active code selection with new Logical channelCommercial ServicesT1/E1 Circuit Emulation supportStress IP Multicast
13 DOCSIS 3.0 Features – Physical Layer CMTS Deployment Models Integrated CMTSImplements the network ports and RF interface ports in a single network elementModular CMTSImplements the network ports and URFI ports in a modular core network element and the DRFI ports in a external EQAMA DEPI tunnel is used to encapsulates the downstream channels from the M-CMTS core to the EQAMA DTI server is used to synchronize the M-CMTS core and all associated EQAM’s
14 DOCSIS 3.0 Features – MAC Layer Downstream Channel BondingAllows a CM to receive data on multiple receive channels using a single service flowAt least 4 channels must be used to equal 150+ MbpsUpstream Channel BondingAllows a CM to transmit data on multiple transmit channels using a single service flowAt least 4 channels must be used to equal 100+ Mbps
15 DOCSIS 3.0 Features – Network Layer IPv6 supportBuilt in support for IPv6Modems can be provisioned using IPv4, IPv6, or bothProvides transparent IPv6 connectivity to CPE’sIP multicast supportSupports delivery of source specific multicast (SSM) streams to CPE’sCMTS controlled layer-2 multicast forwarding mechanismIntroduces “group service flow” concept to provide QOS to multicast streams
16 DOCSIS 3.0 Features – Security CMTS to CM Privacy Features128-bit AES traffic encryption (performed in hardware)Early CM authentication and traffic encryption (EAE)MMH (Multilinear Modular Hash) algorithm for CMTS MIC (message integrity check)Prevent Unauthorized AccessEnhanced secure provisioning featuresSource IP address verification (SAV)TFTP proxy and configuration file learning;Certificate RevocationEncryption support for new method of multicast messaging.EAE = Early Authentication Encryption
17 DOCSIS 3.0 Features – Network Management (cont) Security ManagementIETF deprecated the previous NmAccess approachIn order to address the new D3.0 features and the IETF’s decision:Extensions were built to report configuration status, error conditions and statistics of the new security featuresReplacement of NmAccess is required using a method compatible with the SNMPv3 frameworkAccounting ManagementSNMPv3 polling/trappingIPDR (IP Detail Record) support is expanded to include the new D3.0 featuresNew D3.0 features primarily include channel bonding, M-CMTS, IPv6, and IP Multicast- IPDR defines a way to stream the export of accounting records with less resource taxing. IRDP was supported in the D2.0 OSSI spec, but expanded upon.
18 CableLabs DOCSIS 3.0 Qualification Tiers BronzeDS channel bondingIPv6 CM provisioning without dual stack, basic IPv6 forwarding for CPEBasic DOCSIS 2.0 multicast features, IPv6 multicast support for CM provisioningNo US channel bonding, No S-CDMA, No AESSilverBronze features plus:US channel bondingAdditional IPv6 supportAES, SSM, Bonded multicast, S-CDMA w/o bonding, parts of IPDRGoldFull DOCSIS 3.0 support
20 Downstream Bonding - Features Packet bonding of a minimum of 4 channelsDelivers in excess of 150 Mbps and 50 Mbps USNon-disruptive technologySeamless migration from DOCSIS 1.x/2.0M-CMTS and high density I-CMTS cardsEQAMsNew hardware required for scalability and cost reductionNew CM silicon required
21 Channel BondingIn a nutshell, channel bonding means data is transmitted to or from CMs using multiple individual RF channels instead of just one channelChannels aren't physically bonded into a gigantic digitally modulated signal; bonding is logicalWith DOCSIS 3.0, data is transmitted to modems using multiple channelsWith DOCSIS 1.x & 2.0, data is transmitted to modems using one channelLet's say you want to increase the downstream data rate between the CMTS and modems from today's single 6 MHz wide channel limit of Mbps.If you were to spread your downstream data payload across four 6 MHz wide channels, the combined raw data rate using 256-QAM on each channel would be Mbps x 4 = Mbps.A DOCSIS 3.0 modem incorporates a special tuner capable of simultaneously receiving data from those four channels. To the modem, the four channels are the logical equivalent of one large bonded channel, even though we're using four physically separate channels. They don't even have to be adjacent channels!Want more? Bonding, say, 10 channels, will yield Mbps x 10 = Mbps, and bonding 24 channels works out to 24 x Mbps = 1, Mbps, or just over 1 Gbps. Yikes!The same channel bonding concept is applicable to the upstream, giving us the ability to go far beyond DOCSIS 2.0's per-channel limit of Mbps. How does 4 x Mbps = Mbps—or more—sound?
22 DOCSIS 3. 0 Downstream Channel Bonding with Today’s DOCSIS 2 DOCSIS 3.0 Downstream Channel Bonding with Today’s DOCSIS 2.0 DeploymentsUniversal Edge QAMWideband MACTraditional Cable ModemsWCMWideband DownstreamD3.0 CMDocsis 3.0 Bi-Dir CMCMTraditional DOCSISWideband Bearer ChannelThe relationship of Wideband and traditional QAM modulators is shown in the figure above. Traditional DOCSIS CMs share a common downstream and are spread across several upstreams. The WCM uses the same traditional infrastructure and adds more downstream or upstream capacity. The multiple QAM carriers within a Wideband channel are coupled together to form what looks like a multi-carrier PHY. The coupling does not actually occur in the PHY; it occurs within the transmission convergence layer between the MAC and PHY. This is very significant because it implies that large pipes – upwards of a Gigabit – can be constructed out of today’s inexpensive QAM technology. The Wideband Protocol will support any number of QAM carriers, although the implementations of the WCMTS and WCM will set operational limits.22
23 DOCSIS 3.0 Registration Diagram D3.0 CM acquires QAM/FEC lock of DOCSIS DS channelSYNC, UCD, MAP messagesD3.0 CM performs usual US channel selection, but does not start initial rangingMDD messageD3.0 CM performs bonded service group selection, and indicates via initial rangingB-INIT-RNG-REQ messageD3.0 CM transitions to ranging station maintenance as usualUsual DOCSIS initial ranging sequenceDHCP DISCOVER packetDHCP OFFER packetDHCP REQUEST packetDHCP RESPONSE packetTOD Request/Response messagesTFTP Request/Response messagesD3.0 CM provides Rx-Chan(s)-ProfREG-REQ messageREG-RSP messageD3.0 CM receives Rx-Chan(s)-ConfigD3.0 CM confirms all Rx ChannelsREG-ACK messageUsual BPI init. If configured
24 Reasons DRFI went Beyond D2.0 RFI Applies to CMTS, D3.0, or multi-carrier CMTS DS connectorCleaned up ambiguity in 2.0 and lowerNoise dBmV changed to dBcAllows more channels per connectorDOCSIS 2.0 and lower was only single carrierM-CMTS architecture & D3.0 both reference DRFILess expensive E-QAMs, MxN mac domainsPerformance goal was analog protection given analog ch lineup of 2-13 ( MHz)Digital chs justified to upper end of spectrumCriteria was 60 dB CNR for all combined sourcesNot necessary for digital communication nor sparser lineupdenotes the logarithmic power ratio relative to the strongest carrier in the channelblock. The out-of-band spurious emissions requirements assume a test condition with a contiguous block of Ncombined channels commanded to the same power level, and for this test condition "dBc" should be interpreted asthe average channel power, averaged over the block, to mitigate the variation (see Table A–3) in channel poweracross the block, which is allowed with all channels commanded to the same power.
25 Single Carrier DRFI Annex A & B Channel BW 8 & 6 MHz Variable depth interleaverHRC, IRC64 & 256 QAMdBmVN=1 : 601Harmonic Related CarrierIncremental Related CarrierCenter FrequencyMust 91 <-> 867 MHzMay 57 <-> 999 MHz
26 Single Carrier DRFI (cont) In-band spurious, distortion & noise MERUnequalized MER > 35 dBEqualized MER > 43 dBIn-band spurious & noise ≤ -48 dBcSpurious & noise within ±50 kHz of carrier excludedPhase noise (single carrier)kHz: -33 dBckHz: -51 dBc50 kHz - 3 MHz: -51 dBcDouble sided noise power
27 Single Carrier DRFI (cont) Output return loss>14 dB within active output ch from MHz>13 dB within active output ch from MHz>12 dB in every inactive ch from MHz>10 dB in every inactive ch from MHzPower accuracy per channel +/- 2 dBRF muting ≥73 dB below aggregate power
28 Power Output for Multiple Carriers per RF Spigot dBmV160-ceil[3.6*log2(N)] dBmV121231234RF muting ≥73 dB below aggregate powerNdBmV16025635445284916453242Why is it done like this?Multiple chs create more pwr & distortionsAttempt to keep constant wattage outputDS laser concerns (Pwr/Hz)
29 Step Size ≤ 0.2 dB (configuration granularity) Multi-Carrier DRFIIn-band spurious & noise ≤ -48 dBcSpurious & noise within ±50 kHz of carrier is excludedWhen N > 1, noise outside Nyquist BW is excludedPhase noise (multi-carrier)kHz: -33 dBckHz: -51 dBcDouble sided noise powerdBmVStep Size ≤ 0.2 dB (configuration granularity)Power Diff (adjacent ch) ≤ 0.5 dBPower Diff (non-adj ch) ≤ 1.0 dB1234
31 DOCSIS 3.0 DS Considerations Frequency AssignmentsCMTS may be limited to 860 MHz or 1 GHzCM’s may be limited to 50 or 60 MHz passbandTesting and maintaining multiple DS channelsPhysical channels have not changed for DOCSIS 3.0Test equip with built-in CM’s need to support bondingDS isolation issuesDS channel bonding max power with 4 freqs stackedFour channels stacked on 1 connector limited to 52 dBmV/chDOCSIS 1.x/2.0 DS is 61 dBmV max output
33 Upstream Bonding Service Drivers Competition against FTTHDeliver 20+ MbpsHigh BW residential dataUser generated contentVideo and photo uploadsProliferation of social sitesVideo conferencingTelePresenceCommercial serviceHigh BW symmetrical data servicesBonded T1High BW Ethernet/L2VPN service
34 Upstream Bonding - Features Packet Striping of a minimum of 4 channelsDelivers in excess of 50 MbpsAES and scalability require hardware upgradeNew CM silicon requiredPhased and seamless technology migration
35 Upstream Channel Bonding Upstream bondingSingle flow can consume all BW on multiple USsContinuous Concatenation & Fragmentation (CCF)Improved form of concatenation and fragmentation that is needed for DOCSIS 3.0 operationThe CM has a buffer with a 1000 bytes to send. Its requests for 1000 on US1,the CM receives grants on US1, US2 and US3. The size of the grant may dependon the load on that channelThe CM does not send packets since the grant might not align with packetBoundariesInstead the CM sends “segments”Each segment has a sequence number, and a pointer field so that individual packetsCan be extracted (the pointer field is similar to the one used on the MPEG pointerIn the DS
36 D2.0 is Still Not Used 27.2 Mbps total aggregate speed Achieved 18 Mbps for single CM on USFragmentation and concatenation with a huge max burstLinerate possible of ~ 27 MbpsMake sure 1.0 CMs, which can’t fragment, have a max burst < 2000 B2.0 increases the EQ tap length from 8 to 24Supported in ATDMA & mixed modeOff by defaultThere are other factors that can directly affect performance of your cable network such as the QoS Profile, noise, rate-limiting, node combining, over-utilization, etc. Most of these are discussed in detail in:Knowing what throughput to expect is the first step in determining what subscribers' data speed and performance will be. Once it is determined what is theoretically possible, a network can then be designed and managed to meet the dynamically changing requirements of a cable system.Reject(na) indicates a reject nack. This can occur when a 1.0 modem doesn’t respond correctly to the DOCSIS mode of the US port it is connected to.Right now, load balancing is not supported with DOCSIS 2.0 settings because of load balance weights. Weights are related to the aggregate speed of the “pipe”. In a mixed (DOCSIS 1.x and 2.0) environment, the 1.x CMs could have a weight of and the 2.0 CMs could have a weight of 15 Mbps.Symbol Rate, ksym/secChannel Bandwidth, MHzQPSK Raw Data Rate, MbpsQPSK Nominal Data Rate, MbpsQAM-16 Raw Data Rate, MbpsQAM-16 Nominal Data Rate, MbpsQAM-64 Raw Data Rate, MbpsQAM-64 Nominal Data Rate, Mbps12801.62.5126.96.36.199.686.925603.210.249.215.3613.851206.420.4818.430.7227.5
37 Upstream Adaptive Equalization Example Upstream 6.4 MHz bandwidth 64-QAM signalBefore adaptive equalization:Substantial in-channel tilt caused correctable FEC errors to increment at a rate of about 7000 errored codewords per second (232 bytes per codeword). The CMTS’s reported upstream MER (SNR) was 23 dB.After adaptive equalization:DOCSIS 2.0’s 24-tap adaptive equalization—actually pre-equalization in the modem—was able to compensate for nearly all of the in-channel tilt (with no change in digital channel power). The result: No correctable or uncorrectable FEC errors and the CMTS’s reported upstream MER (SNR) increased to ~36 dB.This slide illustrates an example of upstream pre-equalization in action. To demonstrate the performance of DOCSIS 2.0’s 24-tap pre-equalization, a cable modem was set up to transmit a 6.4 MHz-wide 64-QAM signal at a center frequency of 48 MHz. This frequency forced the signal through the rolloff area of the cable modem’s internal low pass filter, causing substantial in-channel tilt. The upper photo shows the 64-QAM signal as received by the CMTS without adaptive pre-equalization, and the lower photo shows the same signal at the CMTS input after the modem’s adaptive pre-equalization was turned on.Before adaptive equalization: The in-channel tilt caused correctable FEC errors to increment at a rate of about 7000 errored codewords per second (232 bytes per codeword). The CMTS’s reported upstream unequalized MER (“SNR”) was 23 dB.After adaptive equalization: The modem’s 24-tap pre-equalizer was able to compensate for nearly all of the in-channel tilt (with no change in digital channel power). The result: No correctable or uncorrectable FEC errors and the CMTS’s reported upstream unequalized MER increased to ~36 dB.
38 DOCSIS 3.0 Upstream Channel Bonding Bonding process is controlled by the CMTSBandwidth grants are given per flow across one or more upstream channels as CM’s make requestsNew packet streaming protocol called Continuous Concatenation and Fragmentation.Allows a looser coupling between requests and grantsEnables the CM to have multiple requests outstanding simultaneouslyBonding MechanismUpstream channels are synchronized to a master clock source
39 DOCSIS 3.0 US Considerations Frequency Stacking LevelsWhat is the CM max output with multiple channels stackedCould it cause laser clipping?Diplex Filter Expansion to 85 MHzIf amplifier upgrades are planned for 1 GHz, then pluggable diplex filters may be warranted to expand to 85 MHz on the US…one truck rollStill must address existing CPE equipment in the field and potential overloadMonitoring, Testing, & TroubleshootingTest equipment needs to have D3.0 capabilitiesAs explained for DS considerations, any new technology will have some trade-offs and potential pitfalls that we must understand and plan for in advance. The following will discuss some of these issues:Why it’s Needed – This can range from competitive pressure, to higher tiers of service, to more customers signing up.Frequency Stacking Levels & Placement – What is the modem maximum US output with four channels stacked and do the channels have to be contiguous?Isolation Concerns – Whenever applications have different service groups, we have overlaid networks. Signals destined for one node could “bleed” over to another.US Frequency Expansion to 85 MHz – Amplifier upgrades are occurring now. It’s best to make the truck roll once. Think about diplex filters, line EQs, step attenuators, taps, etc.
40 DOCSIS 3.0 Upstream Input Spec To address this potential issue where a modem today transmits near max power of 54 dBmV for 64-QAM, the specification has changed the CMTS US port level setting to allow it to be 6 dB lower. This means the CMTS can be set lower so modems can be placed on those high value taps without changing HE or plant losses. This is at the expense of lower MER/SNR readings.The lowest setting on the CMTS today is -1 dBmV for 6.4 MHz wide channel. The range allowed on the CMTS is dictated by DOCSIS 2.0 and lower and says -1 to + 29 dBmV for 6.4 MHz and related to channel width, also known as symbol rate or baud.D3.0 identified this potential issue and forced D3.0 CM vendors to support a transmit of 3 dB higher than the 2.0 spec. So 64-QAM has to at least max out at 57 dBmV with a single channel.To keep the CM inexpensive, constant wattage device, etc, the max output will be dictated by how many US frequencies are active on the port for bonding. Four channels stacked will be 57-6 = 51 dBmV per ch. So, the overall effect from 2.0 to 3.0 is really 3 dB difference. I can see why the spec lowered the nominal setting allowed on the CMTS so cable operators didn’t need to lower tap faceplates or drop padding on every US port on the CMTS to keep D3.0 CMs online if they max out.Most systems will leave the default of 0 dBmV and adjust padding appropriately. Cisco has a command to keep CMs online that are maxed out, power-adjust continue 4 (default). Many customers set it to 6 to give some more room to work with.
41 DOCSIS 3.0 US Considerations (cont) US Frequency and Level Issues Max Tx for D QAM for 1 channel is 54 dBmVD3.0 US channel max powerTx for D3.0 TDMAdBmV (32 & 64-QAM)58 dBmV (8 & 16-QAM)61 dBmV (QPSK)Tx for D3.0 S-CDMAdBmV (all modulations)Max Tx per channel for 4 freqs stacked at 64-QAM ATDMA is only 51 dBmV & 53 for S-CDMAAs with DS issues, there are also US issues that need to be addressed. US bonding has not been pursued at this point because most people haven’t even exploited D2.0 US capabilities. This does not mean we should avoid the potential issues that will arise. Eventually, we will want to offer US speeds greater than what a single channel modem can offer of ~ 25 Mbps. This will require more US spectrum, D3.0 CMs, and CMTS linecards with US bonding capability.Some of the potential issues are levels and frequency assignments. Activating multiple frequencies per US connector on a 3.0 CM has different max power per channel vs a D2.0 CM. Max transmit for a D2.0 CM using 64-QAM for 1 channel is 54 dBmV.D3.0 US channel max power is: dBmV when using 32 & 64-QAM, 58 dBmV when using 8 & 16-QAM, & 61 dBmV when using QPSK. D3.0 S-CDMA US max power is: dBmV for all modulations.As shown above, it can be seen that the max power for 1 channel on the connector has been raised by 3 dB over a D2.0 CM, but max transmit per channel for four frequencies stacked using 64-QAM ATDMA is only 51 dBmV & 53 for S-CDMA.US passband has also changed in the D3.0 specification. Frequency assignments were 5 to 42, 55, & 65 MHz for Euro-DOCSIS, but it has been extended to 85 MHz. The option of going higher is good for future spectrum re-allocation and avoiding known bad frequencies on the US. Some things need to be considered though and that includes, diplex filters, line EQs, step attenuators, and CPE overload. If incorporating any of these devices in the plant, they may need to be replaced for the new frequency split. Also, can current customer premise equipment (CPE) like settops and TVs handle a potentially high level of “noise” from a modem at 50 MHz or higher?
42 DOCSIS 3.0 US Considerations (cont) US MER/SNR Issues Increasing channel width from 3.2 to 6.4 keeps same average power for single carrierSNR drops by 3 dB or moreKeeping same power/Hz could cause max Tx level from CM’s and/or laser clipping/overloadEqualized vs unequalized MER readingsModulation profile choicesQPSK for maintenance, 64-QAM for Data, 16-QAM for VoIP?Pre-EQ affectGreat feature in 1.1 & > CMs, but could mask issuesAs explained for DS considerations, any new technology will have some trade-offs and potential pitfalls that we must understand and plan for in advance. The following will discuss some of these issues:Why it’s Needed – This can range from competitive pressure, to higher tiers of service, to more customers signing up.Frequency Stacking Levels & Placement – What is the modem maximum US output with four channels stacked and do the channels have to be contiguous?Isolation Concerns – Whenever applications have different service groups, we have overlaid networks. Signals destined for one node could “bleed” over to another.US Frequency Expansion to 85 MHz – Amplifier upgrades are occurring now. It’s best to make the truck roll once. Think about diplex filters, line EQs, step attenuators, taps, etc.
43 DOCSIS 3.0 US Considerations (cont) Channel Placement Frequencies can be anywhere in US passband and do not need to be contiguousIt may be wise to keep relatively close so plant problems like attenuation and tilt don’t cause issuesCM should have some dynamic range to allow specific channels to be a few dB different vs. other channelsChannels are separate and can have different phy layer attributes such as modulation, channel widthSince each US channel used for bonding is an individual channel, frequencies can be anywhere in the US passband and do not need to be contiguous. Although, it may be wise to keep relatively close so plant problems like attenuation and tilt don’t cause issues. The CM should have some dynamic range to allow specific channels to be a few dB different vs. other channels. Since the transmitters (channels) are separate, they don't have to be contiguous and can have different physical layer attributes like; modulation, channel width, tdma or scdma, etc
44 ATDMA General Deployment Recommendations After increasing CW to 6.4 MHz, measure & document unequalized US MER at multiple test points in the plantUse PathTrak Return Path Monitoring System linecardOr Sunrise Telecom Upstream Characterization toolkit25 dB or higher Unequalized MER is recommendedLess than 25 dB reduces operating marginCheck US MER as well as per-CM MERPick freq < 30 MHz - away from diplex filter group delayMake sure latest IOS version is running on CMTSTurn on Pre-EqualizationMany times doubling the US channel width will indicate more issues with the plant than actually increasing the modulation to 64-QAM. Linear impairments like group delay and micro-reflection will not be apparent with a spectrum analyzer, but will severely degrade US modulation error ratio (MER). MER is also known as US SNR as listed on the CMTS. After increasing the channel width to 6.4 MHz, it’s imperative to measure and document unequalized US MER at multiple test points in the plant. Unequalized means per-CM US MER without pre-eq activated. Some tools that can be used include: JDSU PathTrak Return Path Monitoring System linecard or the Sunrise Telecom Upstream Characterization toolkit.The recommended unequalized MER is 25 dB or higher. Less than 25 dB reduces operating margin. Be sure to check US MER as well as per-CM MERIf group delay is suspect in addition to long amplifier cascades, it may be necessary to pick a frequency below 30 MHz, away from diplex filter group delay.If group delay is an issue and difficult to overcome with frequency placement, it may be possible to activate Pre-Equalization for per-CM low MER issues.Be sure the latest IOS version is running on the CMTS and proper modulation profiles.
53 Bandwidth Management Solutions SDVOffer more HD and SD content using less total RF spectrum with the same STBOnly transmit the content being actively watchedCould make more QAMs available for DOCSIS and VOD if QAM sharing is implementedNode splitsPhysically reduce the homes passed per HFC node, thus reduce contention per home for Unicast servicesDecombine more attractiveTriggers additional QAMs and CMTS Ports
54 Bandwidth Management Solutions (cont) Traffic “Grooming”MPEG-4Broadcast to narrowcast QAM injectionReduce broadcast domains to smaller DOCSIS & video service groupsUltimately a complete Unicast lineup on a per node basisAnalog reclamation for more digital spectrumMore QAM channels for Digital Broadcast, VoD, SDV and DOCSISUse every channel availableManage the channel lineup, fill in the gaps, mitigate noise to enable all spectrum1GHz upgradeMake new spectrum for new CPE above 860 MHz
55 1GHz Bandwidth Enhancement & Segmentation 1 GHz Upgrade1GHz Bandwidth Enhancement & SegmentationNetwork Impact<= 750 MHz of BW may not be enoughNode splitting & SDV alone do not solve HFC BW problem1 GHz BW upgrade required1GHz Network BenefitsValue added capacity60 analog 6 MHz chs gainedMinimal cost per home passed cost to implementElectronic-only drop-ins in most cases1 GHz is a cost-effective tool to increase broadcast and narrowcast BW
58 Initial Migration Goal Deliver very high speed data serviceDeliver 100+ Mbps DSDeliver 50+ Mbps USReduction of node split costMultiple DSs per nodeM-CMTS or I-CMTS load balancingMultiple USs per nodeLeverage existing ports and deploy 2.0 USsBW flexibility & reduction of CMTS port costBreak DS/US dependence i.e. independent scalability of US and DSReduce cost of DS ports by more than 1/10Reduce CMTS port/subscriber cost by 30-50%
59 Migration Strategy Target CMTS upgrades in high priority markets FiOS & U-Verse competitive marketsHigh growth & demographicsMarkets with capacity issuesYour node Add more DS QAMs per service group and load balancingVia I-CMTS and M-CMTSCurrent 1x4 mac domain leaves US strandedIncrease capacity to existing 1.x/2.0 modem
60 Migration Strategy (cont) Deliver targeted bonded DS channels to DOCSIS 3.0 CMsVideo and data convergenceVideo and DOCSIS service group alignmentDSG & Tru2way will leverage DOCSIS DS BWShare & leverage existing assetsUEQAMs for VoD, SDV and DOCSISUERM to enable QAM sharing
62 What is VDOC?Solution for the delivery of managed IPTV services over a DOCSIS networkBroadcast TV and VoD servicesTV, PC, and other devices in the homeProvide user experience subscribers expect from their cable operator62
63 IPTV – Even better on cable Fat Pipes – DOCSIS 3.0VBR videoIP/IP signaling/bearer channel as opposed to IP/MPEGOne Network (voice, video, data) to deliver them allDelivery to alternate CPE outlets – PCs, Wifi PDAs (iPhone)“Off-net” possibilities63
64 Channel Bonding creates efficiency gains Big Channel “Packing Advantage” No more room for HD2 additional HD streamsHDHDUnbonded channels create inefficient boundariesBonding drives efficient “Packing”Benefit variesMPEG2/4 HD/SD mixBonding group size10 SD + 5 HD streamsSDHD10 SD + 5 HD streamsHDHDSDHDSDSDChannel capacityHDSDSDHDSDSDHDHDSDSDHDSDSDSDSDHDSDSDSDSDSDSD123412344 separate QAM channels4-channel bonding group64
65 Efficiency Gains from VBR Video Support 40 – 60% more streams with VBR videoLaw of large number works in favor of VBR statmux in fat pipeAs opposed to constant bitrate (CBR), VBR files vary the amount of output data per time segment. VBR allows a higher bitrate (and therefore more storage space) to be allocated to the more complex segments of media files while less space is allocated to less complex segments. The average of these rates can be calculated to produce an average bitrate for the file.65
66 DOCSIS 3.0 Channel Bonding Concepts A CM is unaware of the concept of bonding groups; it is only aware of the set of downstreams it must tune to and the flows it must forward, as instructed by the CMTSA CM can receive traffic from multiple BGs simultaneouslyBonding groups may have different aggregate BW based on services supported, ie 1 BG = HSD and another BG = IPTVDifferent CMs in a Service Group can receive traffic from different bonding groups, ie different BGs based on subscription levelsCM may tune to a subset of the downstreams configured for a SGNumber of receive channels on CM does not need to equal number of RF channels allocated to DOCSIS service (HSD/VoIP/IPTV)66
67 Bonding Group Selection A CM can receive traffic from multiple BGsOperator can steer flows to particular BGs by configuring Service Flow attributes for each BGCMTS uses SF-attributes when selecting BG for a flowOperator could choose to set aside a BG for Cable IPTV and a separate BG for HSD/VoIP67
68 DOCSIS 3.0 Channel Bonding Separate DS bonding groups for HSD/Voice and IPTV CMTSIntegratedor ModularService Group 1HSD/VoIPVideo HeadendIPTVIPTV SystemCMCMCMSTB / PCSTB / PCSTB / PCInternetIPTVService Group nVoIP SystemHSD/VoIPCMCMCMSTB / PCSTB / PCSTB / PC68
69 RF Spanning Initial low-penetration IPTV deployments CMTSIntegratedor ModularService Group 1HSD/VoIPVideo HeadendRF SpanningIPTV SystemCMCMCMPCPCSTB / PCIPTVInternetService Group nSimilar to “wide and thin” in SDV deploymentsVoIP SystemHSD/VoIPCMCMCMPCPCSTB / PC69
71 Cisco DOCSIS 3.0 DS Solution Deployed Worldwide Today DOCSIS 3.0 Bronze functionalityFlexible M-CMTS Design>2x DS capacity with incremental D3.0 module upgrade40 to 184 DOCSIS DS ports7Gbps CMTS SolutionDS channel bonding and narrowband currently supported on IOS 12.3(23)BC and 12.2(33)SCBCompatible with all versions of the 5x20 including S,U, and HUS channel bonding supported in the Bighorn IOS release (FCS November 2009)US channel bonding supported on the 5x20H, 3G60, 20x20Supports >50,000 RGU’s per uBR10K• Capacity for 24 DOCSIS Annex B and 18 Annex A downstream channels• Integrated DOCSIS Media Access Control (MAC) processing• Connectivity to QAMs using dedicated dual Gigabit Ethernet interfaces (SFP based)• On-board packet-bonding engine that stripes IP packets across multiple DOCSIS downstream channelsThe Cisco 1-Gbps wideband SPA performs all traditional and wideband DOCSIS processing of egress packets, including BPI+ encryption. The wideband MPEG packets are aggregated and encapsulated using the DOCSIS 3.0 packet-bonding technique (that is, User Datagram Protocol [UDP], IP, and Ethernet protocols [that is, packets are DOCSIS over wideband MPEG over UDP over IP over Ethernet]).Expands the current 30-Mbps service portfolio options up to 240 MbpsProvides a flexible and easy option to more than double the downstream capacity to the Cisco uBR10012.Transcript:I think most people are familiar with the SPA technology, this is what we call our SPA interface processor, the SIP card, code named Saratoga, this is a shipping SIP card. It's the card with which we've got the DOCSIS 3.0 Bronze functionality. It allows you -- like we were talking about flexible, modular CMTS design. It takes the uBR10K from 40 downstreams capacity today to 88, because you can have two of your downstream SPAs installed at 24 each, so 48 plus 40's 88. We support advanced 2.0 and 3.0 load balancing with the SPA technology and the SPA downstreams, full Layer 3 feature set packet cable and so on and so forth. The most interesting and operationally impacting feature of the SPA is that, like we briefly mentioned, the 5x20s and the RF cabling and wiring remains exactly the same on the 10K. The SPAs are add-on on the WAN side of the box. There's a GigE connectivity between the SPAs and your Edge QAM devices and it has very little operational impact on your existing services. And we support, as we said, advanced load balancing of 2.0 modems between your 5x20 downstreams and the add-on SPA downstreams at the same time that you might be running bonding services on the SPA downstream channels.Author’s Original Notes:Why Narrowband?Continue to utilize the large installed base of legacy modemsAbility to increase the number of narrowband downstream channels in existing CMTSsSimultaneous support for legacy modems at higher speedsSupport for 3-channel bondingAbility to bond all channels of multi-channel CMAdditional downstream capacity100 Mbps downstream data rates on a 3-channel modemProvides support for mixed mode of operation for new QAMs
72 Cisco DOCSIS 3.0 DS Solution Narrowband enables legacy DOCSIS [1.x/2.0] modems to use external QAMs for operationLoad Balancing and DCC techniques 1 – 4 are fully supported on SPA EQAM DS channels.determine CM is an eMTA & initiate DCC to HA DSUses M-CMTS compliant Edge-QAM (EQAM) devicesUses M-CMTS compliant DTI timing source for DS channelsFull Layer 3 IP routing feature setAdvanced QoS, VoIP, PCMM and MPLS VPN support for bonded servicesThe downstream Wideband channel is created by taking DOCSIS frames, putting them into MPEG-TS packets, and placing those MPEG-TS packets onto QAM carriers. However, instead of placing those MPEG-TS packets “horizontally” in time along a single QAM carrier as is done in traditional DOCSIS, the Wideband protocol places those MPEG-TS packets “vertically” across the QAM carriers assigned to a Wideband channel. A DOCSIS frame is literally tipped on its side and striped our across a group of QAM channels.
74 DOCSIS 3.0 Potential Option 5 DS freqs3 US freqs2x5 domainRemoteDSsLocalDSs3.2 MHz6.4 MHzThis diagram graphically shows fiber nodes vs frequency allocation with pros and cons of this scenario. This allows load balance of legacy modems between 2 DS frequencies and bonding on 4 DS frequencies. This requires 5 DS frequencies on the plant and 3 US frequencies.We can use dcc tech 4 to load balance Basic subs across the local DS and one e-qam primary. If modems have a DS frequency in their config file, use “load balance exclude static strict” so only dynamic load balance takes place.ProsFour bonding freqs / e-qam connectorOnly 1 e-qam connector per 8 nodesBasic = 2 DS/2 nodes with DCC supportUS load balance of 2.0 CMsOne US connector shared across 2 nodes for diminishing D1.x CMsConsRequires M-CMTS architectureRequires five DS & three US freqsMust push 3.0 CMs to remote DSBonding group must be same IP bundle
75 DOCSIS 3.0 Option 1 Wiring Diagram This diagram displays how DSs are potentially combined with e-qam modulator DSs and then split to feed multiple service groups or fiber nodes. Downstream four is not used and its associated USs are used in the four mac domains. Upstream connectors use internal frequency stacking on even connectors 0-14 and external stacking on connectors
77 DOCSIS 3.0 Solution for the uBR7200VXR Series UBR-MC8x8U---Extending UBR7200 Series to DOCSIS3.0 Full DOCSIS 3.0 complianceDS bonding/US bondingLegacy DOCSIS 1.x and 2.0 modem supportMulticast, IPv6 and other DOCSIS 3.0 specsS-CDMA and logical channelsAES encryptionSame form-factor as current UBR-MC28U line card, upgrade is simple LC swapOperates in 8 DS/8 US mode on UBR7225VXR and UBR7246VXR, 4x DS density of the existing MC28U line cardRequires UBR7200-NPE-G277
78 DOCSIS 3.0 evolution with the UBR10k MC520H with D3.0 SPA88 DS solution with DS bondingMC520H with 6 D3.0 SPA, PRE4 and 10G184 DS solution enables 5+ DS per FNUS Bonding on the MC520HEnables higher US rate service offeringsMC2020Full D3.0 capability and line rate US bondingEasy upgrade from 520H; interoperable with the D3.0 SPAMC3G60Enables 8+ channel DS bonding at scaleScales US by 3x
79 US Channel Bonding on MC520H DOCSIS 3.0 2, 3, and 4 channel US bonding supported100 Mbps throughput on US bonded flows per line cardDOCSIS Line rate on D2.0/Non-bonded CMBPI+ and PHS support for 3.0 and 2.0 flowsDynamic BW sharing between 2.0 and 3.0 flowsFeature supports provisioning 3.0 CM in bonded or non-bonded configurationDifferent US rates supported in Bonding GroupFor example: 16QAM/3.2Mhz + 64QAM/6.4Mhz
80 Cisco uBR10K MC2020 Linecard Full DOCSIS 3.0 support DSCB USCB IPv6 MCastAESUpgrade for MC520 LCsSame RF CablingVery low operational impactGreater than 7x DS capacity in same 10K footprintGrow from 40 DSs to 304 DSs with MC2020 and six D3.0 SPAs>10Gbps CMTS solutionFull HA support80
81 MC2020 Features Full DOCSIS 3.0 compliance DS bonding/US bondingLegacy DOCSIS 1.x and 2.0 modem supportMulticast, IPv6 and other DOCSIS 3.0 specsS-CDMA and logical channelsAES encryptionLine rate performance on US and DS on all channels (Annex A/B)MC2020 as Protect for MC520 and MC2020Full Feature parity with MC520PRE2/PRE4 supportInteroperable with the DOCSIS 3.0 DS SPASW licensing0x20V, 5x20V, and 20x20v SKUs5 DS, 15 DS, and 20 DS upgrade licenses will be made available
82 MC2020 with MC520H in the same UBR10K chassis MC2020 in 2 slots configured as “Working”1 MC2020 configured as “Protect”MC520H occupy other RF slots (“Working”)MC2020 acts as Protect for BOTH MC520H/MC2020SPA slots can be occupied by 6 D3.0 DS SPASlots FilledDS SpigotsDS ChannelsMC520H525 (5 * 5)25MC2020210 (2 * 5)40D3.0 SPA6 (SPA Slots)6 GigE144MC2020 as ProtectFor 520H and 2020Total DS channels in this configuration= 209
83 Cisco uBR10K MC3G60 Linecard Greater than 12x DS capacity in same uBR10K installed chassis576 DS (504 DS with HA)~20Gbps DOCSIS connectivity10Gbps backhaul3x US capacity480 US (420 US in HA)Up to 12:1 freq stacking on US portsScalable and efficient uBR10K and RFGW-10 matchingFull HA on 10K and RFGW-10MC3G60MC3G60MC3G60MC3G60MC3G60MC3G60MC3G60MC3G60USGEDSRFGW-1083
84 3G60 Highlights Full DOCSIS 3.0 compliance Line rate DS bonding/US bondingLegacy DOCSIS 1.x and 2.0 modem supportMulticast, IPv6 and other DOCSIS 3.0 specsS-CDMA and logical channelsAES encryptionDEPI M-CMTS15 Mac Domains per LC72 DS channels and 60 US channelsN+1 LC redundancyFlexible US and DS ratios (4/8/16/24 channel DS bonding)SW licensing options
85 Bandwidth Growth / Capacity Transition Points 10K Migration 20x20SpumoniSaratogauBR10K scales well ahead of maximum bandwidth demand3G60 supports high-capacity V-DOC in 1 chassis through 2015
87 New Technology Cornerstones DOCSIS channel bonding for higher capacityEnable faster HSD serviceMxN mac domains nowEnable video over IP solutionsM-CMTSLower cost downstream PHYDe-couple DS and US portsI-CMTSAllows higher capacity in same boxSame wiringNew technologies are being pursued to address the DS bottleneck conundrum.DOCSIS 3.0 uses a channel bonding technique to achieve higher capacity links, enable faster high speed data (HSD) service, and provide M x N MAC domains to enable video over IP solutions.The idea of multiple grants per request or outstanding requests with DOCSIS 3.0 is also a good idea for US speed, but still doesn't fix the CPU issue on the CM.The modular CMTS (M-CMTS) architecture is promoted to achieve better DOCSIS economics, lower cost DS PHY, and de-couple DS and US ports. One day we may see fiber optic nodes with DOCSIS physical layer chips embedded so we can use ingress cancellation at the node, digital links from the node back to the headend without the need to amplify, and no more laser clipping. Of course, this means all traffic needs to be DOCSIS-based on the US!The integrated-CMTS idea is a way to use “off-the-shelf” external QAM boxes and the existing CMTS just for US connectivity. This allows return on invest and no “fork-lift” upgrades of the CMST chassis and/or limited cabling changes.
88 DOCSIS 3.0/M-CMTS Concluding Remarks Promises ten times BW at fraction of costIntroduce new HSD service of 50 to 75 MbpsBackward compatible with existing DOCSIS standardsAllows migration of existing customers to higher tier and DOCSIS 3.0 capabilityAllows more BW for legacy DOCSIS 2.0 CMAllows for a phased deploymentIPV6, US bonding, and other features will followDOCSIS 3.0 enables a media-rich user experience with:Faster speedsMore devicesService convergenceDOCSIS 3.0 provides the tools required to build a scalable, efficient, cost-effective access networkCisco DOCSIS 3.0 solutions provide industry-leading scalability, density and cost performance