Unraveling Multimodality with Large Language Models.pdf
Service-Assured Video over DSL Chipset
1. - 80% MPEG
OPTIMIZED ARTIFACTS
FOR IPTV
+ 30% VIDEO
PAYLOAD
1/5 THE
LATENCY > THAN 1/2
ACCESS COST
+ 50% FURTHER
REACH
Solving the Video Delivery problems
of VDSL2
copyright 2005,
Confidential and Proprietary Rim Semiconductor, Inc
2. Ensuring the highest quality video experience
- 80% MPEG
OPTIMIZED ARTIFACTS
FOR IPTV
+ 30% VIDEO
PAYLOAD
1/5 THE
LATENCY > THAN 1/2
ACCESS COST
+ 50% FURTHER
REACH
copyright 2005,
Confidential and Proprietary Rim Semiconductor, Inc
33. the U-Drive Test Bench
for the 26Mb/s digital home
VOIP GAMING / MUSIC HDTV-1 HDTV-2 HDTV-3 SOHO / VPN VOIP
VDSL2
EMBARQ
DISTANCE FROM THE CENTRAL OFFICE AMBIENT NOISE / INTERFERENCE
LOW HIGH LOW HIGH
copyright 2005,
Confidential and Proprietary Rim Semiconductor, Inc
Welcome to Rim Semiconductor Incorporated. Our mission is to deliver the next generation of chipsets for Video over Copper and overcome the inherent limitations of VDSL2
Our next-generation VDSL chipset is called Embarq. Embarq(TM) is the only legitimate IPTV transport processor capable of satisfying: the carriers’ core business goals the video requirements of the access network and the revenue goals of the equipment manufacturer The significant differentiators of Embarq are: 30% higher bandwidth payload for video 50% longer reach over copper an 80% reduction in both packet latency and MPEG artifacts for video less than ½ the cost of VDSL2 for access network deployment
While VDSL2 is promising HDTV delivery over copper, Embarq offers the only DSL architecture specifically tailored to meet the specific transport needs for HDTV video over copper. We say this because for carriers to implement cable-competitive video services, they must be able to install a video over copper solution capable of delivery 26Mb/s to the home.
Let’s understand why 26Mb/s is the necessary target bandwidth. While SBC’s IPTV lab is targeting 20Mb/s, we believe realistic service for the Digital Home requires 26Mb/s. Both analysts and the US Telecom Association are targeting 26Mb/s because IPTV service must expect subscriber demand for 3 simultaneous HDTV channels, in addition to T1 rates for internet access and ½ a Meg for derived voice. For the copper carrier to install a video infrastructure capable of competing head-to-head with cable, they must not only deliver 21 Megs of video, but also maintain video QOS while the family: operates a home office, downloads streaming music, browses the internet, and enjoys online gaming.
In view of this realistic demand for the digital home, VDSL2 serving 20Mb/s just does not measure up. Shown here is the payload of VDSL2 compared the the payload of Embarq as measured at 6000 feet from the DSLAM or CO.
Over 30% of rural telcos in the US are already offering some form of video service. And the balance are planning installations within the next two years. But to deliver services adequate to attract cable customers, the carriers’ new video access network must support the full range of Video-on-Demand, Pay-per-View, and regular HDTV programming to which subscribers are now accustom. This is wy we say that 26Mb/s is the realistic target for the Digital Home, and why we say Embarq is the only DSL option ready to legitimately support the core business goals of today’s copper carrier.
When comparing actual measured bandwidth over 24 AWG copper for Embarq, we have demonstrated a 50% increase in range for our 26Mb/s service versus the claims of VDSL2. And in confidential meetings with equipment vendors testing actual VDSL2 chipsets, they tell us that they are not even able to realize these claimed goals for VDSL2 reach and bandwidth
To put a finer point on why we are focused on video, we believe that video is the Killer Application for DSL. Yet video brings new – more stringent - requirements to the digital access network. We all know that voice service cannot tolerate more than a few milliseconds of delay, or messages become unintelligible. Yet we can hear words amidst a moderate noise background. Data - on the other hand - cannot tolerate noise for it creates bit-errors. But packet data protocol does accommodate delays by re-sending corrupted data Finally video cannot tolerate either because while the noise corrupts the image quality, packet re-sends are not tolerable without interrupting video’s streaming flow So while the last decade’s focus on data and voice has created robust access technologies, the unique needs of video have not been fully addressed yet by copper solutions.
So we believe the inherent limitations of VDSL2 are not adequate to solve the needs for today’s video access needs: 20Mb/s at 6Kft is not adequate bandwidth for cable-competitive broadband a 4Kft reach is not adequate since that doubles the cost of an access deployment, compared to Embarq the overhead allocated for VDSL2 QOS is not adequate to protect the video stream VDSL2 is simply an inadequate extension of old VDSL technology and does not provide the kind of fresh DSL thinking required to make video-over-copper commercially successful for carriers
In fact, by plotting the history of xDSL efforts, we can see how VDSL2 is an extension of old VDSL thinking, and how many VDSL2 vendors are trying to tack on fruitless work-arounds to make VDSL2 appear attractive. Yet all these workarounds are simply not required, are too costly, and do not make sense in view of Embarq’s breakthrough performance. And from the equipment vendor’s viewpoint, only Embarq’s performance advantage will provide the breakthrough network performance - both in bandwidth and cost - that can give the DSLAM maker an advantage against Alcatel’s world-renown dominance
In attempting to deliver video-optimized DSL, Embarq brings important advances to the science and engineering of DSL. Fundamentally we are addressing the long-standing goals of DSL: to advance the distance to which higher bandwidths can be served To assure maximum possible Ethernet payload over that bandwidth To make sure that payload has QOS optimized for video services. Actual measured results of our system performance have extended the delivery of 26Mb/s From 4Kft with VDSL2 to 6 Kft using 24 AWG copper, achieving a 50% improvement in reach.
Since we are focused on video as the Killer Application for DSL, we wanted to demonstrate the importance of packet delay and jitter on the HDTV signal quality. Specifically, the packet re-sends that are so familiar and tolerated in internet traffic, simply destroy the HDTV picture quality that is dependent on a reliable 9Mb/s feed. MPEG compression exploits the slow-changing portions of the video frame, so image motion is the first aspect to be compromised. And then fine-resolution detail - the hallmark of HDTV – is also degraded significantly
Avoiding introduction of these MPEG artifacts is Embarq’s goal. Artifacts are the visual result of digital delay and jitter - and are created when corrupted data must be re-sent. Once a re-sent packet arrives, it can then be reconstituted with additional errors like out-of-order and duplicate packets, further degrading video streaming. Finally, every instance of packet loss and the resulting digital artifacts are “memorialized” up the protocol stack. So errors introduced at the physical layer cannot be removed, and are added to the entire protocol error accumulation. Embarq’s system latency is 80% lower than VDSL2, meaning VDSL2 will deliver 5 times more MPEG artifacts, shown in the next slide.
If you look closely you can see a demonstration of the loss of picture quality resulting from VDSL2’s 80% higher rate of latency and video jitter.
So to optimize video delivery over copper, our fundamental approach has been to leverage fresh thinking in four technological opportunities for managing noise and reducing latency at the receiver. By doing this we can more closely approach Shannon’s Limit than any of our competitors, and thus deliver superior DSL performance, optimized specifically for the needs of video transport over copper. The four key areas in which we have developed a fresh DSL solutions include: a video-centric bandplan which avoids VDSL2’s nailed-up upstream allocation using a time-division approach that enables up to 98% downstream allocation that maximizes video streaming a more noise tolerant approach that uses smaller frame sizes a dynamic noise adaptation approach that increases payload throughput a receiver-side processing method that avoids the latency inherent in VDSL2’s DSLAM entraining
Now lets see how each of these fresh DSL design approaches contributes to the Embarq solution.
The need for 21Mb/s of downstream video to serve 3 HDTV channels is daunting. Yet VDSL2 has permanently allocated 20% of it’s bandwidth to upstream data. In the historical context of internet useage, this makes sense, but not for video-centric service. While voice and internet traffic will continue to need upstream allocation, Embarq’s adaptive symmetry will elegantly accommodate upstream demand, yet also support maximum downstream payload for video.
To avoid a nailed-up allocation of the copper spectrum, Embarq is based on Time-Division Duplexing (TDD) scheme, in contrast to VDSL2’s use of Frequency-Division Duplexing (FDD). Note how the FDD bandplan allocates upstream / downstream segments of the copper frequency spectrum. These are rigid bandplan allocations which permanently tie up 20% of the DSL spectrum to upstream processing. Embarq uses TDD to allocate upstream signals on an as-needed basis. When upstreaming is required, Embarq allocates a short burst of time and uses 100% of the copper spectrum. In the remaining time, 100% of the spectrum is allocated downstream. This approach provides two key advantages for video transport: Downstream Bandwidth throughput capacity is continuously increased by 20%. Since video streaming is 99.9% downtream, This 20% gain in bandwidth capacity can be applied 99.9% of the time. Of course, when other voice and data services require upstreaming, the upstream allocation increases. But for pure video transport, Embarq delivers an immediate 20% gain And this 20% gain in performance using TDD is on top of the performance gains enabled by our advanced noise management techniques described earlier 2) Symmetry is adaptive on-the-fly to match customer demand Since no triple-play solution must accommodate upstream traffic, the ideal solution is to enable flexibel symmetry that responds to fluctuating demand pattersn The VDSL2 approach of permanently nailing-up bandwidth is obviously self-limiting, especially for video-centric applications 3) all sensing & switching performed at receiver, introduces no DSLAM training
The next set of slides will show how we manage noise better than VDSL2. To achieve this, Embarq has adopted the short frame-size approach. This is because short frames (derived from short symbols) can survive the bursty noise inherent in DSL transmission lines. Copper lines typically induct noise from a wide range of sources that are highly transient over time. Thus the long frames inherent in VDSL2’s DMT approach are more suseptible to interference, while More of our short frames can survive intact by inter-leaving between the moments of lower noise.
To achieve the short-frame approach, we adopted the wideband modulation scheme used earlier in CAP systems.
However single-carrier wideband sacrifices too much power over long copper reaches. Thus we created a hybrid between CAP & DMT we call Multi-carrier Wideband, or MultiWideband ™ We carved the wideband modulation scheme into 10 discrete multi-tone channels so that each channel can be Power-adapted to match the attenuation characteristics of the copper transport.
In addition to Embarq’s frequency-based noise management using our 10-channel multi-carrier, we also implement time-based noise tolerance using our short frame size. Short frames deliver an inherent noise robustness without using any dynamic signal processing, by simply taking advantage of the momentary lapses in noise power. In contrast, long frames are more vulnerable to noise spikes over time. This hypothetical time-domain diagram demonstrates the survivability of short frames compared to VDSL2’s DMT-based long-frame approach. With more packets requiring resend, latency goes up, degrading video picture quality significantly.
Also note that when Embarq packet are re-sent, their small size enables faster response to achieve faster recovery of payload. This faster recovery further reduces latency and jitter for video. Additionally, the entire voice, video, & data payload is more readily jeapordized by noise in VDSL2.
Additionally, we also leverage our short-frame advantage using dynamic signal processing. Very little overhead is required, because we are not directly processing the payload, but rather adaptively moving the noise rejection floor. VDSL2 employs a fixed signal-to-noise reference level, below which it rejects all payload. In contrast, we take advantage of short frame sizing to send data during brief periods of relative quiet to constantly adapt to varying noise levels with a dynamic, adaptive signal-to-noise floor. This approach can yield up to an 8dB of additional gain, available intermittently. Assuming this gain is available only 15% of the time, (between noise spikes) our Adaptive Noise Management can yield an average 1Mb/s of additional payload throughput.
Embarq’s Adaptive Noise Management – in concert with its inherent noise tolerance in both the time & frequency domains – is all achieved at the receiver end only. This receiver-side noise management eliminates the need for entraining the DSLAM, which the VDSL2 approach requires. The following slide illustrates the latency that DSLAM entraining requires.
Here we see the 3-step process of VDSL2’s approach to dynamic noise management called “adaptive bit loading”. When the VDSL2 receiver senses a drop in intermittent noise, it signals the DSLAM to boost the bit-rate. Then the DSLAM ramps up the bit-rate it sends to the CPE. In contrast, the Embarq line card in the DSLAM is constantly sending at a maximum full bit-rate, without the delay and bandwidth overhead required by DSLAM entraining. Note that the latency required by VDSL2 training results in the jitter and delay that directly jeapordizes video QOS.
In addition to reducing latency by removing DSLAM training, Embarq’s short frame size also minimizes video delay by recovering faster from packet losses. Since our frame size is only 1/50 that of VDSL2’s, our clock cycle to re-transmit damaged packets is 100 times faster. Operational testing has measured an aggregate 5:1 reduction in latency at the system level
So let’s summarize Embarq’s architectural approach vs VDSL2 Basically the need for optimizing a video access network requires two key components: An asymmetrical ratio favoring video’s downstreaming nature. A level of payload QOS that minimizes video delay & jitter The first issue of symmetry is addressed using the TDD vs. FDD bandplan approach. The second issue of payload throughput is a function of managing noise. The manner used by VDSL2 to address both of these needs is inherently crippled, and not the type of system architecture one would design if trying to optimize video delivery. In contrast, Embarq’s approach is clearly tailored to fit the specific needs of the video access network and thereby achieves: the superior performance required by video up to 60% cost reduction for access deployment due to extended reach fully integrated triple-play Ethernet solution
Now let’s examine some of the specific benefits Embarq brings to the Equipment Manufacturer
This chart from In-Stat shows that the VDSL integrated circuit market is growing about 24% per year, and that in 2006, it will be about $220 million. I would point out to you that while this is a large market, the projections do not take into account the positive impact that VDSL2 will have. We believe that because VDSL2 now opens up new services that were previously unachievable, the growth curve will get steeper. But this is not the end of the story. VDSL2 does not really give the telcos the HDTV strategy that they want, as we have discussed. Embarq has the potential to dramatically speed up the whole market, because it finally solves the biggest problem. We believe that Embarq has the potential to not just enter the market, but to actually shift it into a much higher gear!
So in addition to building greater demand for video over copper, Embarq will assure equipment makers a more responsive development team – one willing to listen to the specific preferences of the manufacturer and adapt to their needs. Additionally, manufacturers can realistically charge more for the Embarq solution based on its superior performance at ½ the deployed cost of VDSL2 (see following access cost slides) Finally, we believe this combination of outstanding value can help equipment makers compete successfully against Alcatel’s global dominance of DSL sales.
Rim Semiconductor intends to make our exceptional value completely clear and unassailable using this “U-Drive Demo Bench” The diagram shows that a 26Mb/s source feed consisting of the standard “digital home” bandwidth streams will be split to run through both the VDSL2 and Embarq chipsets simultaneously. An actual copper loop simulating the RT-to-home feed will be provided. The length of this loop can be controlled by any visitor to change form 2Kft up to 6Kft so that the resulting attenuation of bandwidth can be observed. In addition, the visitor can turn on or off any desired bandwidth source such as VOIP, VPN, or any of the three high-definition TV channels
The process for monitoring the resulting bandwidth will include: 6 HD monitors (3 for each chipset) w/ hi-def surround-sound speakers so actual picture and sound quality can be observed in real-time HDTV dropout meters measuring signal loss for each channel Bandwidth performance meters measuring both the raw Ethernet bandwidth, and the ratio of the Aggregate VDSL bandwidth versus the delivered Ethernet bandwidth – intended to demonstrate and quantify re-transmission error ratesFinally, this “U-Drive” test bench will also let visitors adjust minimum QOS levels for video, VOIP, etc so that we can demonstrate: that we have a viable EMS component in our product, and that we have not artificially embedded favorable QOS setting
Finally, let’s evaluate Embarq’s impact on the copper carrier. As we have said, Embarq’s more robust video delivery will let the carrier compete more aggressively against cable for subscribers - and in fact can leap-frog cable services running on analog DOCSIS plants. Perhaps most important is that Embarq assures these advantages at a 50% cost reduction compared to VDSL2. This access plant cost saving - coupled with the fact that the copper plant is already paid for – can help carriers end up with a higher Return-on-Investment from video-over-copper than cable companies
26Mb/s @ 6Kft lets carrier leapfrog analog cable services with turnkey broadband solution supporting bundled voice, video, & data at lower system cost than Digital Cable
The video-over-copper access solution will use the “IPTV” consortium for programming. This consortium will assure subscribers the choice of over 10,000 channels. In comparison to cable’s fixed channel choices, IPTV is already demonstrating its mass appeal and has been shown by industry surveys to be a potent force in helping carriers capture cable subscribers
In fact, once the carrier decides to aggressively install such cable-competitive services, he will likely realize a higher ROI than cable companies
But perhaps most compelling is Embarq’s reduction in deployment costs for the video access network.
Now Mr. Salesman, study these slides, and then write your own summary here as a test of your understanding
Our contribution to DSL can be evaluated in the context of historical DSL efforts. In that continuum, we can observe that VDSL2 is a natural extension of VDSL, And as such, includes baggage from previous efforts that limits possible advances. Much of the late VDSL2 development efforts are actually work-arounds that attempt to play catch-up to mitigate the limitations inherent in the VDSL2 evolution scheme. At Rim Semiconductor, we are simply asking, “ If you were designing a video access network today, would you design around VDSL2?”