Content as Network

Hero Worshiping

It is kind of rare to meet your hero in person. Rarer yet is to be able to work with your hero on a regular basis.

So, it is a pretty mind blowing for me to say that I sit only a few doors down from Van Jacobson (http://en.wikipedia.org/wiki/Van_Jacobson) who is the primary contributor to TCP/IP which in term provides the foundation for internet as we know it today.

Content Centric Networking (CCN)

Van is leading the effort for content centric networking (CCN). This is a high level talk that he gave a while back that explains what he has in mind.



CCN for the rest of us

Naturally, if you are not fully conversant with the 7 layers of network protocol hierarchy, e.g. business development folks like me, too need an answer on what is CCN.

This is what I say, we are working on the next generation of internet. :-p!

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I hope to explore the roadmap and implications of CCN in periodic entries. Suffices to say, the CCN group is very busy at work right now.

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P@P

Can 802.11 cut the HD TV cords?

802.11/WiFi for HDTV

For those of us in the know, 802.11 is the de facto wireless standard for computing devices that comes with all wireless PC/laptop and is increasingly available with mobile handsets and gaming console.

So the logical question is can 802.11 become the de facto wireless standard for all electronic devices. Say, instead of wiring up my new HDTV with all the players and other devices, would something like 802.11 help cut the cords?

This is an issue that a lot of industry players are grappling with and the latest verdict, for whatever it is worth, is yes according to this analyst report "802.11n Wi-Fi Technology is the Spoiler at the Wireless HD Video Party; Will Dominate (http://in-stat.com/press.asp?ID=2513&sku=IN0904455MI)"

Reality Check

Instead of arguing over the technical details, we conducted an analysis on how 802.11n will perform in typical home scenarios. Think of it as simulations on how 802.11n will work in a perfect environment - so your performance at home will only be worse...

Assumptions

It turns out that working out the specific variable/assumptions are the most tricky part. So, this is what we came up with. We want a home environment where there are different type of wireless traffics: some web surfing, some VoIP chatter, some TV watching, and some Blu-ray video watching.

We also looked into the distances amongst all the devices because interference is a very real issue with 802.11. As things are further apart, there is less inference and vice versa.

So, here are the variables that we tried in our simulations.

Devices:

Blu-ray video
HDTV
Media center (MC) - provides Blu-ray and HD TV to, up to, two (2) TV's
Web session
VoIP call
Access Point (AP) - support the web and VoIP sessions

Distances:

Short - 3m/10ft
Medium - 10m/30ft
Long - 15m/50ft

Scenarios

Without being exhaustive, scenarios range from:

Most “forgiving”: 1 MC + 1 HDTV + 1AP + 1 VoIP + 1 Web at long distance (15m/50ft)

to
Least “forgiving”: 1 MC + 1 Blu-Ray + 1 Blu-Ray+ 1AP + 1 VoIP + 1 Web at short distance (3m/10ft)

Results

The performance threshold that we used was less than 200msec delay. If it is more than that, it becomes noticeable to human perception.

The long and short of it is that 802.11n only works within the acceptable range in the case of one HDTV far away from other devices, i.e. the most "forgiving" scenario. On top of it, all the other users such as web surfing and VoIP would have to accept significant performance hit.

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I would love to hear your experiences using 802.11 in a mixed-media environment with multiple users. Maybe I am missing something here.

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Context Aware Protocol Engines (CAPE)

Ad Hoc Networking at PARC

As the birth place of Ethernet, PARC has maintained a presence in networking technology over the years. And, one of the areas that PARC is working on explores the ad hoc networking technology.

CAPE (Context Aware Protocol Engines) came out of several lines of work related to wireless ad hoc networking. A major early driver/consumer of this type of technology is DARPA with military application in the battle field where the operating environment is highly dynamic and ability to effectively communicate commission critical.

However, like most technology, there are many civilian commercial applications that may be worth exploring.

CAPE

Without going into the details, CAPE sets up a wireless network that is self-configuring, scalable, high-utilization, and high-quality. Specifically, here are some of the advantages that we have been able to demonstrate vis-à-vis conventional solutions such as 802.11.

Higher throughput: conventional solution has a fair amount of traffic management overhead whereas CAPE was designed to minimize the overhead required. In practice, this means that for a given bandwidth (pipe size), CAPE can pack a lot more traffic into it.

Better Quality of Service: looking beyond throughput, a major network issue for the end-user is jitters and delays for real-time streams such as video VoIP calls. While the payload may not be large in absolute terms, the sequence and speed of delivery are vital to its smooth function. Again, this is an area convention solutions often fail and CAPE can maintain a high QoS level.

Multi-Hop: for those of you who have to deal with multi-hop ad hoc networking issue, you know how big of a challenge this is. Suffices to say that CAPE allows for quite a few hops without requiring special antenna or extensive topological engineering.

Self-configuring: since it is not reasonable to expect a soldier to spend 5 minutes setting up network access in the heat of battle, CAPE allows each node in the network to self-configure as the node comes into the network. In the more mundane world, where I live, this means that when mom buys a new laptop, I do not have to configure it for her!

What can you do with CAPE?

I am looking into application areas for CAPE. I would love to hear your ideas and suggestions.

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