Caltrans’ New Technology and Research Program
Instructor: Kevin Almeroth
March 21, 2001
Another technology being investigated for ATON is digital video segmentation, which is used to extract images of individual vehicles and their respective shadows from a video feed of a surveillance camera looking at traffic on a state highway. This will enable computers to automatically detect incidents or congestion. The system being developed by the ATON researchers uses a distributed activity recognition database that decomposes complex activities into spatio-temporally bounded primitive events, stores them, and provides querying mechanisms to retrieve them. The query mechanism includes rules for composition of complex activities. For example, a “collision of multiple cars” is a complex activity that is defined as a set of patterns of less complex activities. These patterns are built from primitive events like “car stops suddenly” or “car enters a region,” where the “region” has been pre-define as a part of the road, as seen from the camera’s view, not normally traveled by vehicles. The primitive events are detected by visual and other signal processing layers and can be limited in number. The complex activities are exponentially greater in number, but it is not necessary to define them individually. In order to provide the researchers with more data, I’m working to set up a video server using “Video Logger” software from a company called Virage and “Real Producer” from Real Networks. I’ve compiled several video tapes of various types of traffic patterns and incidents by tapping into live video feeds in the Caltrans District 7 TMC (Traffic Management Center) in Los Angeles. Operators in the TMC can select from, and simultaneously monitor, several feeds from cameras on freeways and city streets in the Los Angeles area. The technology being developed by the ATON project will enable computers to constantly monitor the camera feeds and alert the operators of detected activity. I’ve procured and installed two video capture cards in the computer on which I installed the aforementioned software. I will use this system to encode the analog NTSC video signal from a VCR into compressed, streamable digital files. Once encoded, I can define and index clips from the files showing specific traffic behavior and post them as hyperlinks to be retrieved by the researchers. The communications medium for this will be the CalREN-2 network, which I’ll mention in more detail a little later.
I’m also working to render an animated computer simulation of a robotic incident response system as envisioned by the ATON researchers. Using a program called Maya, from Alias Wavefront, I have modeled a system that travels on the concrete median or “K-rail” of a freeway to an incident site and deploys a CMS (Changeable Message Sign) to alert motorists of the incident, ODVS and rectilinear cameras to allow remote operators to closely monitor the incident site, and wireless-controlled vehicles carrying expandable cones to cordon off the area of the incident. I still intend to animate the model and add elements such as background, lighting, textures and surface reflectivity to make it look realistic. In the mean time, you can try to get an idea of the mechanics of the model in the low-resolution Figures 1a through 1h.
Figure 1a Figure 1b
Figure 1c Figure 1d
Figure 1e Figure 1f
Figure 1g Figure 1h
CalREN-2 is short for California Research and Education Network, and links various California Universities and research institutions via high speed OC-12 and OC-48 fiber optic connections. I am currently working to establish an OC-3 (155 mbps) VC (Virtual circuit) from our facility on the UCSB campus to the Computer Vision and Robotic Research Laboratory at UCSD. This involves establishing a physical single mode fiber link from our facility to the main UCSB switch room, which is about a mile away. This link will be between the Fore ASX 200BX ATM switch in our facility and a Cisco Lightstream ATM switch in the switch room. The Fore switch has interfaces for both single and multi-mode fiber interfaces, but the Cisco switch only has multi-mode interfaces. Because or this, I procured a media converter from Black Box that will sit in the switch room between the two ATM switch ports. (Please see note 1 in Figure 2.)
Another thing I did in preparation for this link was work with UCSB Communications services to update the configuration of the router that connects the LAN in our facility to UCSB’s main backbone fiber. The CalREN-2 VC will effectively extend a portion of this LAN to the Computer Vision and Robotic Research Laboratory at UCSD. In order to prevent anyone there from hooking this portion onto another subnet and routing other UCSD or Internet traffic across the CalREN-2 VC (or even running spoofing attacks by "impersonating" a host not on our subnet), we set up "access lists" that only permit routing (in-bound and out-bound) of packets whose addresses start with the class C network address of our LAN, which is a good security precaution in general. We also did a few other things to “modernize” the configuration. The router had been running RIP, which we changed to OSPF (open Shortest Path First). This enabled it to communicate with more other routers at UCSB (also running OSPF) directly, without having to go through a RIP/OSPF translation server. Also, it can now choose an alternate route to the Internet if its regular gateway router goes down. This gateway router had previously had a static route set up to forward traffic destined for our subnets to our router, and it advertised this route on our router’s behalf. Now, our router advertises its own subnets, and can route outgoing (outside UCSB) traffic through any router on the UCSB backbone that has a path to the Internet. This didn’t change the load on its CPU significantly; it is still under 10% in the steady state. We added NTP (Network Time Protocol) which enables the router to log events by time of day to aid in troubleshooting. We added SNMP (Simple Network Management Protocol) so a configuration management server can get our router’s configuration file and store it for backup purposes. For security, we specified that SNMP messages can only be exchanged between itself and the configuration management server.
I’ve submitted the administrative paper work and, at this point, I’m waiting for the group that controls access to CalREN-2 to authorize the OC-3 bandwidth allocation.
Network Modifications for Office Relocation
During the Winter 2001 quarter, we moved our off-campus facility to another location within the Pacific Technology Center. Besides moving equipment, this involved relocating and re-terminating two data communications media (in addition to moving the POTS--“Plain Old Telephone Service” lines). One of these is an ISDN (Integrated Services Digital Network) PRI (Primary Rate -- 1.472 Mbps) line, which we use to connect our video conferencing system to our multipoint video conferencing bridge as well as other video conferencing systems at Caltrans and its research partners. The physical medium for this line is a “D-screen” cable containing two shielded twisted pairs which were terminated to pins 1, 2, 4 & 5 (as opposed to 1, 2, 3 & 6 as in Ehternet) of an RJ-45 jack on a patch panel. The layer one protocol is a T-1 line, which is leased from Verizon. The layer two protocol is the ISDN signaling, which is transmitted on channel 24 of the T-1 line and allows for switching of calls at MCI’s DMS 250 switch (just like a POTS line). Our terminal equipment for this line is an Ascend MAX 6000 IMUX (Inverse Multiplexer) which, in turn, connects to a PictureTel Concorde 4500ZX video Conferencing system (please see note 2 in Figure 2). The PictureTel system, as well as other composite NTSC video sources, connect to the analog inputs of a Jupiter NT850 system which is essentially a Windows NT computer with special I/O hardware that enables it to display a composite image on four separate monitors. These monitors are a 2 x 2 array of 52” LCD projection “cubes” from Clarity Visual Systems (please see Note 3 in Figure 2). The system just described allows NTSC composite video (including images of remote video conferencing sites) as well as SVGA video from the computer to be presented on a 104” “video wall” (Please See note 4 in Figure 2).
The other data communications medium is a multi-mode fiber optic pair which is used to connect our terminal equipment, a Fore Systems ASX 1000 ATM, with a Positron Osirus fiber multiplexer in the main communications room of the Pacific Technology Center. The other end of this VC terminates at a similar Positron Fiber MUX in UCSB’s main switch room. Our terminal equipment on campus is Fore ATM mentioned in the previous section. (Please see note 5 in Figure 2.) The data transmitted on this link is IP over LANE (“LAN Emulation”) over ATM (Asynchronous Transfer Mode) over SONET (Synchronous Optical Network). The link enables host PCs at our Pacific Technology Center facility to be logically part of the LAN in our UCSB facility.