Abstract:
The Improved Mobile Digital Video Recorder (IMDVR) system is a ruggedized, multiple camera video and audio recording system that is installed within a public transit vehicle to record, store, and manage an integrated data stream of data captured within and exterior to the transit vehicle. The system is focused on multiple person vehicles and the capture of an integrated data stream for use in transit security, liability, and evidentiary processes.

Description:
PRIORITY 
   This application claims the benefit of priority to U.S. Provisional Application 60/707,523, filed Aug. 12, 2005. 

   TECHNICAL FIELD 
   The 2 nd  Generation Mobile Digital Video Recorder (MDVR) is referred to as the Improved Mobile Digital Video Recorder system or TransitCAM Platform. The TransitCAM Platform consists of the MDVR and all possible components and configurations necessary to support safety and surveillance activities requiring audio, video, and transaction data of evidentiary quality. Various configurations of the TransitCAM platform will serve two primary markets, Public Safety and Transit. This document defines the Product Design Specification for the TransitCam Product developed by Integrian, Inc. The TransitCam product is focused on the Transit market—Municipal Bus, Commuter Rail/Light Rail and ParaTransit/School Bus—with a priority on the safety and surveillance needs of the Municipal Bus market. 
   BACKGROUND 
   This invention relates generally to a mobile security system for mass transit vehicles in which multiple cameras capture a plurality of images that are integrated with sound and data of interest and saved to a storage device. The cameras continuously record images from a plurality of directions and points of view that are of interest in protecting the vehicle and the occupants of the vehicle, monitoring the interior of the mass transit vehicle, and providing a video, audio, and data record of events that are preset as trigger events, such as a collision. 
   Installing a camera in a security vehicle such as a patrol car is known in the art. Attaching a digital video recorder to capture video, audio and text is also know as is shown in U.S. Pat. No. 6,831,556, issued to Boykin et al. However, these systems are intended to provide a record of activities that are from a single point of view, that of the operator of the patrol car, that may be used later in evidentiary proceedings. The systems in the prior art do not address multiple points of view within and surrounding vehicles composed of multiple components, such as those composing a train, or that are more that 40 feet long. Prior art systems also do not address data streams integrated together to provide a complete picture of all activities occurring within the viewing envelope, a continuous record of all imagery, sound, and data for said envelope of interest, with all of the information stored in digital media for real time and after-the-fact viewing by interested parties, such as a transit supervisor or security expert. 
   The Improved Mobile Video Recordation System addresses the shortcomings in the prior art with innovations that develop and hold a defensive audio and video envelope for the protection and safety of the users of a mass transit vehicle. In addition, the imagery data, including audio and other types of data, is continuously recorded to a storage device, with higher quality video automatically stored as the result of a trigger event. 
   The present invention is an elegant solution to the problems inherent in systems that are designed as an adjunct to law enforcement activities and not intended for the broader needs of private companies and agencies charged with providing for the safety and security of users of all types of mass transit. 
   SUMMARY OF THE INVENTION 
   The Improved Mobile Digital Video Recording (IMDVR) System was created as a means to provide for security and safety for users of all types of mass transit systems. The primary means for gathering information about the interior and immediate exterior proximity of the mass transit vehicle is through the use of from two to eight video cameras and a plurality of audio microphones per vehicle or car. The input audio and video data information from these devices is synchronized and combined with data from other input devices that gather operational, control, maintenance, analytic and telemetry data to produce an integrated information data stream. This integrated information data stream is stored in real-time to hi-capacity storage devices installed within a mass transit vehicle, and, in addition, to hi-capacity storage devices located external to the mass transit vehicle. Transfer of the integrated information stream to an external hi-capacity storage device is effected through wired or wireless communication channels. 
   Power is provided to the system from the vehicle power source. The power system includes a separate battery, which is used for smoothing the power profile to the IMDVR system, and emergency charger to insure continuous operation of the recording function. The power supply system also includes a software controlled voting function that decides whether to supply power to the IMDVR from the vehicle source or the battery backup based upon the instant power profile. The power supply system is responsible for adjusting input power to provide a plurality of voltage levels required by the various sub-systems within the IMDVR. 
   The primary mission of the IMDVR is to capture continuous video, audio, data and meta-data information from the moment the system comes online until some time after the vehicle is shut down, said time span being configurable by the user. In support of this mission, the IMDVR utilizes two modes for recording—normal mode and an event mode. Each mode records two separate integrated data streams simultaneously with one integrated data stream recoded in low-resolution and a second integrated data stream recorded in high-resolution. The definitions of low-resolution and high-resolution are user configurable and dependent upon the frame rate, bit rate, and image resolution chosen for each level of resolution, however, low-resolution is configured to result in a smaller storage file size than high-resolution. 
   In normal mode, the low-resolution integrated data stream is saved to the on-board high-capacity storage device in non-erasable data files, and the high-resolution integrated data stream is saved to a portion of the high-capacity storage device that has been constructed as a ring buffer with a configurable storage limit. The storage limit may be set to hold between 1 and 180 seconds of continuous recording of the high-resolution integrated data stream. At the end of the configurable storage limit, the data stored at the beginning of the buffer is overwritten with the most current data from the integrated data stream. This process continues with the most current data overwriting the next position in the buffer such that the buffer always contains the most recent recording of the integrated data stream. This circular buffer therefore contains the most recent 1 to 180 seconds of the high-resolution integrated data stream. 
   Event mode is triggered by a plurality of pre-set events, such as notification by an integral rules engine that a certain speed has been exceeded, a crash has occurred, or the driver hits a panic button, for example, or multiple events such as the opening of a vehicle door when the speed is greater than zero. In event mode, the high-resolution integrated data stream is redirected from the circular buffer directly to the high-capacity storage device in place of the low-resolution integrated data stream. In addition, the circular buffer, containing the previous 1 to 180 seconds of the high-resolution integrated data stream is prepended to the data files created on the high-capacity storage device such that the data from the integrated data stream record now contains a full data record from the configurable time prior to the trigger event until the event mode times out. At which time the IMVDR system returns to normal mode recording. 
   The IMVDR system internal communication is supported by the MDVR data bus and the Inter-Integrated Circuit (I 2 C) bus. The I 2 C bus communicates with the General Purpose Input/Output (GPIO) controller and systems external to the IMDVR that provide data or control information critical to the operation of the IMDVR. These systems include sensing ignition of the mass transit vehicle, the real-time clock, a Global Positioning System (GPS) input, vehicle forward/reverse and speed sense, etc. The MDVR data bus provides communication between all other components of the IMVDR system. 
   The IMVDR communicates stored data files to an external high-capacity storage and retrieval server through wired or wireless communication channels. In wired mode, a user may attach an Ethernet cable to an Ethernet port integrated into the front or rear panel of the IMVDR or, optionally, retrieve the removable on-board high-capacity storage device. If an Ethernet connection is established, data files are transmitted from the on-board high-capacity storage device to the external server, which then saves the files to the high-capacity storage device on the external server. If the removable on-board high-capacity storage device is removed it is then docked with the external server and the files downloaded into the high-capacity storage device on the external server. In wireless mode, the IMDVR establishes a network communication path with an external server through the use of an integral wireless modem. Once the wireless communication path is established, data files are transmitted from the on-board high-capacity storage device to the external server, which then saves the files to the high-capacity storage device on the external server. 
   In addition to the input data streams from video and audio devices, the IMVDR provides standard connectors for a plurality of external systems. These connectors include DB9 and Universal Serial Bus (USB) connectors for attaching external devices to support the mission of the IMDVR. For example, these devices can include a monitor, keypad, output from intra-vehicle data sources such as the Society of Automotive Engineers (SAE) J1708 and J1939 buses, or other devices deemed necessary to the optimal operation of the IMVDR. 
   The invention also involves a computer server and software modules required to configure, operate, maintain, and administer the IMVDR system. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1 : a view of the system diagram. 
       FIG. 2 : a view of the component diagram. 
       FIG. 3 : a view of the software system components. 
       FIG. 4 : a view of the process flow diagram 
   

   DETAILED DESCRIPTION 
   The functionality can be seen split between the MDVR  100  and the power supply  300  unit. There is a serial communications link between the two components for accessing and controlling the various functions. This interface is a 2-wire serial interface. 
   Real Time Clock Operation 
   The real-time clock  502  and associated battery are located in the power supply unit  300 . Access to clock functions will be over an I 2 C interface  500  to the Power Supply Processor (PSP)  501 . The real time clock  502  is polled at power up to set the time for the system. The real time clock can be updated through GPS time data or Network Time Protocol (NTP) during docking. Standard functions include current time and current date. If the MDVR  100  is off, a periodic, repeatable, wake-up alarm (with configurable duration) is used to implement a “wake up and look” scheme for the WiFi interface. 
   Accelerometer Operation 
   The Accelerometer will be located in the MDVR  100  unit. It is a single 3-axis device accessed by the PSP  501  over the I 2 C bus  500 . The accelerometer will measure at minimum 3G with a 0.01 G resolution. 
   The accelerometer can be pre-configured with a threshold. If this threshold is exceeded the PSP  501  will be notified and in turn the PSP  501  will notify the GPP  101  so that appropriate action can be taken. Polling of the accelerometer by the PSP  501  will occur at a maximum of 10 milliseconds. 
   GPS Operation 
   The GPS module  610  will be mounted externally to the power supply  300 . The electrical interface will be via the DB-15 connector located on the power supply interface board. 
   The GPP  101  will communicate directly with the GPS module  610 . The module will generate location messages as well as data reliability information so that an assessment of the readings can be made in software. These will include signal strength, EPE, number of satellites, etc. 
   The GPS  610  incorporates Dead Reckoning (DR) as not only a backup for positioning when satellites are not in view, but also as a sanity check for GPS information in urban canyon environments. To accomplish the DR function, a gyroscope will be used. The gyroscope can accurately measure inertial changes in the X and Y axis. Since the unit can be mounted in either the horizontal or the vertical plane, the gyroscope must also be mounted with the X and Y axis in the horizontal plane. 
   General Purpose Input/Output (GPIO) Operation 
   Twelve general purpose inputs  612  are provided to interface external trigger devices to the system. These inputs are read over the I 2 C bus  500  of the PSP  501 . Through configuration, the inputs can be set for either active high or active low operation. 
   Three general purpose outputs are provided to control devices external to the system. Control of these devices is accomplished via on board relays. Relay contacts are rated for 24 VDC at a maximum current of 1.0 amp. 
   Control of outputs and notification of input triggers is accomplished by the PSP  501  and passed to and from the GPP  101  over the serial interface. 
   Access to the GPIO  600  is done through the terminal block connected to the DB-37 connector on the power supply. 
   Power Supply Operation 
   The power supply  300  generates all primary power used by the system. In consists of six switching power supplies, generating 9.5 VDC  308 , 3.3 VDC  306 , 1.4 VDC  305 , 1.5 VDC  307 , 5.0 VDC  304  and 12.0 VDC  303 . These power supplies are enabled/disabled by a microcontroller  501 , which is powered by its own 3.3 VDC LDO regulator. Additionally, a back up battery  301  is provided that maintains full operation of the system for 10 minutes in case the primary power to the unit is interrupted. 
   The microcontroller  501  not only controls the individual power supplies, but also monitors/controls GPIO  610  external to the unit. It monitors current to the cameras and fans, while also enabling/disabling them as required. 
   Pre-Event Buffer Operation 
   The Pre-Event Buffer is used only in non-event mode (Video only): in this case, two recording for the same video source (one camera per DSP) are performed, one in low-resolution (saved to High-Capacity Storage (HCS  730 )), and the other in high-resolution mode (saved into the pre-event buffer). Note that the pre-event buffer is using the HCS  730  only, and not the memory. There is one HCS file for all video frames between 2 I-Frames, e.g. if the pre-event buffer is configured to hold 30 seconds, and there is one I-frame each 30 frames (30 fps recording), there will be 30 files for each camera input using a pre-event buffer. This method allows an easy file roll-over. 
   HCS Cache Operation 
   An HCS  730  buffering scheme has been implemented in order to minimize the access to the HCS  730  and improve performance. A DSP delivers the Audio/Video (A/V) compressed frames to the core_app  800  program, which queues the frames into a FIFO (Shared Memory Queue). The av_wdisk  811  process reads the frames from the Shared Memory Queue and writes them to the HCS  730 . 
   Instead of writing frames directly to the HCS  730 , the frames are saved in memory, at a location where a dedicated software component can retrieve them at a later time and then save them to the HCS  730 . This process optimizes the disk access time and minimizes the time the HCS  730  is in use, saving electrical and processing power. The HCS cache is implemented as a C++ class, which accepts several parameters to determine operational limits and timing for the process. These parameters include the amount of total memory allocated for the cache, and the percentage of cache used before the data must be stored to the HCS  730 . 
   The HCS cache maintains statistic information that the main application can query and use for information, debugging and tuning purposes such as the maximum cache space utilization, average cache space utilization, minimum, maximum, and average cache flush time, and the average disk writing time (MB/sec). 
   OSD Operation 
   An On-Screen Display (OSD) is provided via a hardware OSD chip placed in line between the video inputs and the hardware video decoders. 
   The OSD inserts text into the video prior to compression. The text includes date, time, and camera name up to 12 characters. OSD information is provided on a per camera basis. 
   The OSD hardware chip may also be placed directly within any one of the DSP&#39;s ( 210 - 214 ), in order to minimize the number of chips required in the system. 
   Wireless Modem 
   The embedded wireless modem is 802.11 g. It is used for video and data transfer to the external system server (TVMS) during docking. The wireless modem is also used for local streaming. In this case a computer with 802.11 g capability in close proximity to the MDVR  100  can view real time video from any camera  250  within the system. 
   Primarily the wireless modem used is from DPAC, which has an Ethernet interface. Additionally, an 802.11 g PCMCIA card may be used. 
   Streaming Operation 
   Live and stored streaming both use the Session Description Protocol (SDP) to describe a streaming session and all media to be viewed within that session. Streaming descriptions include elements from the core SDP standard, RTP/AVP standard, MPEG4 elementary stream standards, and custom attributes defined by the streaming server. A custom library handles SDP generation and parsing. Streaming descriptions are retrieved via HTTP. The client will request the streaming description either 1) when the user initiates playback of one or more video streams, or 2) when the MDVR discovery process determines that live streaming should be started. 
   Live streaming uses a custom RTSP-like command set over HTTP to setup, play, pause and teardown the streaming session. Video and audio elementary stream data are transported using standard RTP packets; the MDVR  100  pushes the packets to the client(s) as live content become available. 
   The stored streaming process uses HTTP to transport video, audio, and data frames to an output device. The client pulls frames as needed from the MDVR  100  using custom URL queries and HTTP headers. 
   Streaming Server 
   The streaming description and control interfaces use the same HTTP server framework as device manager, allowing the streaming server to leverage the same encryption and authentication mechanisms as well. This takes advantage of database and file system access routines from the device manager in order to generate session descriptions and send back stored frame data. The streaming server implements custom handlers within the HTTP server framework for each of the required control and data requests. 
   File Transfer Operation 
   For retrieval of video and audio frames and per-frame information, docking relies on the streaming server and uses the same HTTP requests as the streaming client in order to transfer all or part of an elementary stream. 
   Driver Display Operation 
   An interface to a driver video display is provided  655 . This interface contains power, video, RS-485 communications and contact closure interfaces. A button on the driver display will allow live video viewing to be switched between any of the connected cameras. Depending on the display control interface, this can be accomplished either through the RS-485 communications link or through pulling one of the contact closure lines low. 
   Audio Processing 
   Input audio processing is handled through a stereo codec  410 . This allows up to two channels of audio input to the system. Each audio input can handle either line or microphone levels. The input level selected will be determined by the audio input on the appropriate pin on the connector. Digital audio will be passed from the codec to a DSP for MPEG4 (AAC-LC) compression. 
   Output audio process is also handled by the same codec  410  as the audio input. In this case, the stereo audio is summed to produce a mono audio output at line level. Audio output contains information from a streaming input from a device external to the unit. The audio output does not present live or pre-recorded audio from the MDVR  100  unit itself. 
   Video Processing (Recording) 
   When the TransitCam application  821  is running (which is normally the case after the MDVR  100  has booted), the MDVR  100  is always recording in either non-event (normal) or event mode. 
   Each camera is configurable for recording in low-quality, medium-quality, or high-quality video record mode. The recording modes are configured using parameters such as the frame rate per second (1 to 30), the bit rate (bits per second), and the image resolution (D1, Half-D1, VGA, SIF, etc.). In addition, each camera responds to advanced settings such as the rate control (Variable Bit Rate or Constant Bit Rate), the profile (ASP, SP, or H263), the Scene Quality (low, medium, or high), and the number of I-frames per second. 
   Two cameras are connected to a DSP (up to 8 cameras  200 , and 4 DSPs  210 - 213  are used for video recording). As mpeg-4 encoding is very CPU intensive, it is possible to encode only one of the two cameras connected to the same DSP in the highest-resolution. A video splitter is implemented to allow compression of two separate qualities for one of the cameras connected to a DSP. 
   Normal Mode 
   In this mode the high quality recording for a first camera is stored into the Pre-Event Buffer, on the hard-drive, which can hold a configurable number of seconds of A/V frames. This buffer will begin to be overwritten when the data stored in the buffer exceeds the pre-determined size. 
   Simultaneously, the video frames from a first camera are compressed in the Low (or medium) quality and ‘permanently’ stored to the HCS  730 . The video output from a second camera is also compressed in low (or medium) quality and stored onto the HCS  730 . 
   Event Mode 
   Upon detection of a pre-configured event trigger, the ‘overwriting’ of the pre-event buffer will stop and high quality recording for the first camera is appended and stored ‘permanently’ on the hard-drive. The 1 low (or medium) quality recording for the second camera continues to be stored onto the HCS  730 . 
   The MDVR  100  continues to operate in the current mode until the event trigger is reset and the post-event timer has expired, at which time the MDVR  100  reverts to Normal Mode. 
   Communication Ports Operation 
   Ethernet 
   Three Ethernet ports ( 641 - 643 ) are provided for connection to external devices. Two of the ports ( 642 - 643 ) are located on the rear of the unit. They will operate at 10/100 speed. These ports may be used for an external radio modem, mobile communications router, or for interface to a vehicle logic unit/mobile data terminal. 
   One Ethernet interface is provided on the front of the unit  641 . It will be capable of operating at 10/100 speed and up to Gigabit Speed (Gigabit Ethernet). This port is primarily used for video file retrieval when a wireless method of retrieval is not available or desired. 
   USB 
   Three USB 2.0 ports are provided for connection to external devices. Two of the ports  561 , 562  are located on the rear of the unit. These ports may be used for an external GPS, external radio modem, mobile communications router, or vehicle logic unit/mobile data terminal. Potentially, these ports may also be used for connection to an external mass storage device such as an external high capacity storage server. 
   One USB 2.0 port  563  is located on the front of the unit. This port may be used as for video file retrieval in lieu of the front panel Ethernet port. 
   J1708/J1939 
   The J1708 interface  657  serves as a general-purpose serial data communication interface. The software interface will give the host application the ability to listen to several stand alone modules attached to the serial chain. In a typical J1708 interface, the J1708 protocol serves primarily as the physical and media access functionality. SAE J1587 provides application layer functionality. As defined in the SAE J1708 spec, the software interface will be able to interpret messages matching the 1708 defined format parameters such as the Message Identification Character (MID), data characters, and a checksum. 
   The software will also have the ability to handle message type defined by both SAE J1708 (MID&#39;s 0-127) and application messages defined by SAE J1587 (MID&#39;s 128-255). 
   The J1939 interface is also known as the Car Area Network (CAN). Newer heavy equipment vehicles may use both J1708 and J1939 as a general purpose communications interface between vehicle systems. The J1939 is intended to replace J1708 in the future. The J1939 interface differs from the J1708 in the physical interface as well as the software protocol. The MDVR  100  supports both J1708 (J1587) and J1939. 
   RS-232 
   One RS-232 only port  656  is provided on the rear of the unit. The port will be capable of speeds up to 115.2 kbps. The port will not only support data transmit and receive but also two hardware handshaking lines; request to send (RTS) and clear to send (CTS). Additionally the control line, data set ready (DSR) will be provided so that the MDVR can detect that something is connected to the port. 
   RS-232/RS-485 
   One port  655  is provided that can support either RS-232 or RS-485. The RS-232 will support only data transmit and receive; there will be no hardware handshaking support. The RS-485 will support a two wire differential connection. 
   Hardware Overview 
   Processors 
   The MDVR  100  unit contains three processors;
         The General Purpose Processor (GPP)  101  is a Freescale MPC5200, which contains a Power PC (PPC) core and some integrated peripherals. The GPP  101  manages data between memory (HCS and DDR) and peripherals on the PCI bus (DSP, IDE, USB, etc.),   The Digital Signal Processors (DSPs  210 - 214 ) are Texas Instruments DM642. The DSPs will be responsible for video and audio compression. They will place the compressed data on the PCI bus, where the GPP  101  directs it to the appropriate device,   The Power Supply Processor (PSP)  501  manages the individual power supplies. It will also monitor all GPIO  600  connections to devices external to the unit. The PSP  501  also monitors camera and cooling fan current as well as controlling power to each camera, fan, and heater. The PSP  501  monitors the integrated accelerometer and temperature sensing circuitry.
 
Peripherals and Interfaces
 
Accelerometer
       

   The accelerometer will be a single device, monitoring acceleration in all three axes. The accelerometer will be located on the power supply board and monitored by the PSP  501  over the I 2 C bus  500 . The accelerometer will be capable of measuring up to 3 G at 1 mG resolution. 
   Real-Time Clock 
   The Real-Time Clock (RTC  502 ) is responsible for keeping time. It has a battery back up so that time is kept even when power is removed from the system. The RTC  502  can be updated periodically (once a day) via the GPS  610 , Network Time Protocol (NTP) during docking, or from time supplied by the vehicle logic unit. At startup, the RTC time information is transferred to the GPP  501  and then used to synchronize all activities of the unit (elementary stream time stamps). The RTC  502  communicates with the PSP  501  over the I 2 C bus  500 . 
   GPIO 
   General Purpose Input/Output (GPIO)  610  is monitored/controlled by the PSP  501  over the I 2 C bus  500 . 
   Twelve inputs  612  are monitored and can be configured as either active high or active low through software control at boot up. The inputs are connected to the system via the external connector block. Each input can handle 0 to 32 VDC. The switching threshold is at 3.3 VDC. Input one is configured for ignition sense, so that the system will boot up whenever the vehicle ignition is on. Inputs eleven and twelve are not only routed to the PSP  501  but also to the GPS module  610 . These inputs are used for vehicle forward/reverse sense and speed sense respectively. 
   Three outputs  614  are provided that are used to drive internal relays. The normally closed, common, and normally open contacts of the relays are routed to the connector block, external to the unit. Each relay is capable of handling 1 ampere of current at 32 VDC. 
   Both the input and the outputs are monitored even when the system is in the ‘off’ state, as long as vehicle power is connected to the unit. This facilitates monitoring ignition sense. This feature also facilitates unit activation in a security application by monitoring motion sensors or door contact closures if so configured through software. 
   GPS 
   A Global Positioning System (GPS)  610  receiver is provided as a customer option in the system. The GPS employs Dead Reckoning (DR), which improves position accuracy and provides constant position when the satellite signals used for GPS  610  are blocked by tunnels or urban canyons. 
   The GPS unit  610  is mounted external to the unit and is interfaced to the unit via the DB-15 on the power supply board. The GPS  610  uses two signals from the vehicle; forward/reverse sense and speed pulses (both from the transmission). A gyroscope is used in the GPS unit  610  to detect change of direction. The gyroscope must always be mounted upright; therefore the GPS unit  610  can be mounted either vertically or horizontally depending upon the desired orientation within the mass transit vehicle. 
   Power for the GPS module  610  comes from the unit power supply  300 . Communications with the system is handled over a serial interface to the GPP  501 . 
   Power Supply 
   Power is provided to the system from the vehicle power source. The power system includes a separate battery  301 , which is used for smoothing the power profile to the IMDVR system ( FIG. 1 ), and emergency charger to insure continuous operation of the recording function. The power supply system  300  also includes a software controlled voting function that decides whether to supply power to the IMDVR  100  from the vehicle source or the battery backup based upon the instant power profile. The power supply system is responsible for adjusting input power to provide voltage levels of 12V  303 , 9.5V  308 , 5V  304 , 3.3V  306 , 1.5V  307  and 1.4V  305  as required by the various sub-systems within the IMDVR  100 . 
   MDVR 
   The Mobile Digital Video Recorder (MDVR)  100  is provided as the central record and storage engine within the system. The MDVR  100  includes a microprocessor for inter-process communication and control of all components connected to a primary information bus  101 , which includes all of the following components. The MDVR  100  comprises up to eight cameras  200  strategically mounted in locations to observe interior and exterior scenes of activity in and around the mass transit vehicle. The MDVR  100  also comprises an input for each camera into a video codec  220 , a multiplexer for joining video input and transferring to Digital Signal Processors (DSPs  210 - 214 ). Each DSP receives input from two cameras. The MDVR  100  includes two audio inputs and an audio codec for integrating audio data into the stored information stream. The MDVR  100  also comprises inputs from exterior data sources including a monitor output, keyboard input  655 , input from serial ports supporting third party data sources such as the SAE J1708 and J1939 vehicle area network inputs  657  for recording data and meta-data comprising vehicle performance data, communication connections for external communications such as Ethernet  642 - 643 , Gigabit Ethernet  641 , wireless connectivity through a wireless modem antenna  651 , Universal Serial Bus (USB) connections to external equipment control panels  561 - 563 , and Diagnostic LEDs. The MDVR  100  comprises connections to on-board high-capacity storage devices  730 , and heating  680  and cooling devices to provide for retaining operating temperatures for the storage devices within environmental operational limits. The MDVR  100  is tied together operationally through two high-speed, high-capacity communication buses to provide inter-process communication under GPP  501  control throughout the system. 
   OSD Module 
   On-Screen Display (OSD) is accomplished with a hardware OSD chip. OSD is only in-line with the recorded input. The chip is capable of integrating OSD information on eight inputs. A two-way multiplexer is used to switch between real-time video and OSD on a frame by frame basis, recording OSD video information on one-half of the frames. The OSD chip is controlled by the GPP. 
   Additionally, the OSD hardware can be replaced with a DSP algorithm that will add OSD to every recorded frame. 
   Wireless Modem 
   An internal 802.11 wireless modem  650  is provided in the system. This modem is connected to an internal Ethernet port on the GPP  651 . This modem is the primary means of transferring recorded video, audio, data, and meta-data. Additionally, this modem can be used for video streaming as long as another 802.11 device is in range. The 802.11  650  can make connections via infrastructure or ad hoc on an as needed basis. 
   External wireless modems are also supported. These modems communicate over the cellular network. They are primarily used for streaming low resolution (low frame rate) video to a central point. Connection to the wireless cellular modems may be accomplished over USB  563 , Ethernet  642 , or RS-232  658 . 
   Ethernet Module 
   Ethernet support is part of the integrated peripherals of the GPP  101 . The Ethernet functionality goes through an Ethernet switch  110  that provides four ports. Two ports go to RJ-45 connectors on the rear of the unit  642 - 643 . One port is reserved for an 802.11 internal wireless module  651 . The last port is a spare, but routed to the front panel board connector as a backup to the Gigabit Ethernet  641 . 
   Gigabit Ethernet  641  support is provided by an Ethernet chip on the PCI bus. This port is routed to the front panel board connector for connection to the front panel RJ-45 connector. 
   USB Module 
   Universal Serial Bus (USB) support is accomplished by a USB 2.0 host controller on the PCI bus. This controller supports three USB ports: two on the rear of the unit  561 - 562  and one on the front of the unit  563 . 
   High Capacity Storage Device (HCS) 
   The MDVR  100  supports a plurality of High Capacity Storage Devices  730  including up to four 2.5 inch Hard Disk Drives, or high-capacity flash memory. The HDDs are mounted such that two drives are serviced by one connector on the main board. The HDD are controlled via a HDD IDE controller connected to the PCI bus. The high-capacity flash memory is connected to the PCI bus and controlled by the MPC 5200 through PCI device controls. 
   Audio Codec 
   The audio codec  410  processes both input and output audio to/from the system. Setup for the audio codec is accomplished over the I 2 C bus  500  connected to the servicing DSP  210 - 214 . Audio input and output are stereo line level. Audio inputs at microphone level require filtering and amplification to line level for proper operation. The audio output left and right stereo channels are summed together to provide a monaural output. 
   Video Multiplexers 
   There are three 8:1 video multiplexers  225  used in the system. One multiplexer routes analog video to the live video monitor for real time viewing of video from the selected camera. The other two multiplexers route analog video to the two video decoders used for streaming. 
   Video Decoders 
   Ten video decoders are used in the system. One of the video decoders (eight total) is associated with each camera. Two additional video decoders are used for streaming. Each of these decoders is connected to the cameras through an 8:1 multiplexer. Two video decoders feed each DSP. 
   HDD Heaters 
   HDDs used in the system are capable of operating between −20° C. and 85° C. The low temperature specification for the system is −30° C. At boot-up, heaters  680  are used to raise the temperature of the HDD from below −20° C. to −20° C. at a rate of 1° C. per minute to achieve the proper temperature operation profile. The heaters have an integrated thermistor. 
   Software Processes 
   TransitCam Application 
   The transitcam process  821  starts, stops, and monitors all processes of the TransitCam application. Monitoring the processes consists of polling the system to check if all applications are running. If not, the missing process will be restarted, and the incident will be logged. The transitcam process  821  also monitors how much the CPU is used by the processes, and will adjust the priority of an ‘offending’ process if it consumes too much of the CPU. For instance, recording the A/V files onto the HCS should run at higher priority than the HTML server (configuration). If after adjusting the priority of the process, it is still using 100% of CPU for a ‘long’ period of time (more than 20 seconds), the process will be stopped, then restarted. 
   Shared Memory 
   Shared memory  840  is a first in, first out (FIFO) queue. This queue provides temporary storage of A/V frame for distribution to other applications. The size of this queue is approximately 4 MB, which will allow enough time for the programs reading this FIFO to handle the frames (saving to the HCS, streaming, etc.). 
   Logger Daemon 
   The application logger daemon (loggd)  820  logs events sent by the application processes. The communication between the loggd process  820  and all other application processes is done through shared memory  840 . 
   Depending of the type of the log (system or application), the log will be saved either into a daily text file (system level log), or into a database (application level log): 
   IPC Daemon 
   IPC Daemon  810  handles the communication between the GPP  101  and the PSP  501 . It runs as a separate process on the GPP  101 , and is loaded at a very early stage during system initialization so that some primitive diagnostics are performed on the PSP  501  even before the main application starts. 
   Core Application 
   The core application (core_app)  800  is the main application process. It is primarily responsible for controlling and handling the recording of the A/V streams and provides the A/V compressed frames to the other processes that need them. This application is the only process that interfaces with the DSP  210 - 214  (configure and control). The core application  800  also handles the alarms. The core application  800  is responsible for changing the format of the A/V files, which are recorded according to the state of the system (event mode or non-event mode). 
   The core application  800  stores the compressed A/V frames into Shared Memory, which enables one writer process (core_app program  800 ) and several reader processes (streaming, av_wdisk  811 ). 
   Rules Management Process 
   The rules management process (rules_mgt  812 ) receives input data from various sources (I/O, etc.) and applies a set a configurable rules to determine the status of the system (mainly alarm or non-alarm mode). This information is then be forwarded to the other processes. The rules management process also initiates the generation and collection of meta-data that is incorporated into the integrated data stream and stored in the HCS. 
   A/V Recording Process 
   The A/V files recording process (av_wdisk  811 ) is responsible for writing the integrated data stream onto the hard-disk. It gets the frames from the core application via shared memory. 
   In event mode, this process writes the A/V frames onto the HCS  730  from the pre-event buffer. 
   If the HCS  730  is not available, this process will allow the MDVR  100  to continue recording, but will not save the integrated data stream files until the hard-drive will become available. When the HCS  730  becomes available again, this process will allow the MDVR  100  to start writing the integrated data stream files onto the HCS  730 . 
   Streaming Server 
   The streaming server (streaming  822 ) is responsible to stream out the A/V streams to the streaming client. It gets the A/V frames from the core application via shared memory. 
   Device Manager 
   The Device Manager (devmgr  813 ) is responsible for the Server to MDVR  100  interaction. It also handles the system configuration through the HTML interface. 
   Time Zone 
   All events time stamped within the MDVR  100  (A/V frames, log events, etc.) are using UTC time, and not local time. An environment variable is used by the System to change the way the time is locally interpreted. 
   GPS 
   The GPS interface  610  communicates with the TransitCam platform via NMEA defined messages. In several different NMEA messages, UTC time is available. These messages include the following:
         BWC—Bearing and Distance to Waypoint   GGA—Global Positioning System Fix Data   GGL—Geographic Position, Latitude and Longitude   RMC—Recommended minimum specific GPS/Transit data       

   From the UTC time fix in any of these messages, and the time zone setting of the system, time sync can be achieved. 
   RTC 
   The Real Time Clock (RTC)  502  is a battery-backed clock that is external to the PSP  501 , communication between the two occurs via I 2 C  500 . Upon boot up of the MDVR system  100 , the PSP  501  receives the current value of the RTC  502 . The PSP  501  passes the time information to the GPP  101 . RTC  502  data is supplied to the GPP  101  on a periodic basis and when requested. The RTC  502  is calibrated with the GPS  610  or with network connection during configuration/upload. The RTC  502  data is very accurate and has a difference of +1 second. 
   MDVR Discovery 
   The MDVR  101  and other system level devices that intend to discover it use Zero Configuration Protocols (Zeroconf) to support addressing, naming and service discovery. When an MDVR  101  joins a network or its discovery information (including status) changes, it will push the updated information to all listening clients, who can choose to take further action depending on the information received. A new client who joins the network can query the network for all attached MDVRs  101  and receive their discovery information back immediately. 
   Link Local IP Addressing (IPv4LL) 
   In the absence of a DHCP server or static address configuration, an MDVR  101  assigns itself a random IPv4 address in the 169.254/16 subnet. It is then able to communicate with existing operating systems (including Windows) that already implement this feature, allowing ad hoc local networks to be formed effortlessly. 
   Multicast DNS 
   Multicast DNS (mDNS) provides a mechanism for naming and service discovery on a local link where a DNS server may not be present. DNS queries and responses are instead sent to a locally-scoped multicast address (224.0.0.251, port  5353 ). It can be used whether an MDVR is configured with any of a link local, dynamic or static IP address. Every MDVR assigns itself a unique name in the .local domain based on its serial number. Each advertises its own A and PTR DNS records for forward and reverse lookups, respectively, as well as service discovery records described below. 
   DNS Service Discovery 
   Each MDVR  101  registers PTR records for service types it offers (such as _mdvr._tcp) and SRV records (such as MdvrId._mdvr._tcp) giving the address and port of the service. TXT records provide additional parameters for each service, such as the URL path to access the service or status flags so a client can determine if the MDVR needs attention. 
   Inputs/Rules/Events 
   Input Definition 
   Inputs are values read from peripherals, including among other things the data from GPS  610 , the messages received from the J1708/J1939 bus  657 , and the values read from the GPIO lines  612 . 
   Each of the GPIO lines can be configured to have different meaning (e.g., ignition sense, door open . . . etc.) 
   Rule Definition 
   A rule is an input plus an operator plus a value. Some examples may be “Door open ==true”, “Speed&gt;=65”. 
   Event Definition 
   An event is one or more rules logically ANDed together, and can be associated with zero or more actions. When all of the rules are satisfied for an event, the event is said to be “triggered”. When an event is triggered, a log entry corresponding to that particular event will be logged. In addition, the actions (if any) associated with the event will be carried out. Some event examples may be “(Panic button pressed ==true)=&gt;Start high-res recording (on pre-configured cameras)”, “(Door open ==true) AND (Speed&gt;=10)=&gt;Notify the control center”. 
   High-Quality Recording 
   One possible action for a triggering event is to start recording in high-quality mode. If this action is enabled, when the specific event triggers, the pre-configured cameras will switch to high-quality recording mode. A timeout period will be associated with each event (if high-quality recording is enabled) to resume normal recording mode after the timer has expired. 
   In the case of overlapping triggers (i.e., multiple triggering events whose actions result in the same camera going into high-quality recording mode), the normal recording mode will not resume until the last timer of the group of triggering events has expired. 
   Trigger Notification 
   Another possible action for a triggering event is to notify the control center. If this action is enabled when the specific event triggers a notification will be sent through an internal communication mechanism to a predefined host. 
   Rule Engine 
   The Rules Engine  812  is a separate program that uses the Input Definition and Rules Definition to generate the Triggers, according to the Triggers Definition. Each time a new I/O event is received, the rules are then checked to determine if there is a need to generate a trigger. 
   The Rules Engine program  812  is a high-priority process, designed with optimizations and performance in mind. For instance, for performance reasons, the Rules Engine  812  is using a local copy in memory of the Database tables involved. 
   The Rules Engine program  812  receives input information from the ipcd  810  program, applies rules to computer the Triggers state, and sends the Trigger state to a pre-defined set of programs within the system. The pre-defined programs are the main program (core_app  800 ), the streaming program (streaming  822 ), and the Device Manager (devmgr  813 ). 
   Audio/Video Analytics 
   The collection and storage of audio, video, and meta-data provides opportunities for the IMDVR to provide a number of functions as a result of analyzing the stored data stream in conjunction with the rules engine to search for specific activities and provide indicators when such activities have occurred. Activities that can be recognized and reported upon include:
         Automatic License Plate Recognition   Recognizing a Man Down   Weapons Brandishing/Violent Motion   Gun Shot Detection   Multi-Camera Rendering   People Counting   Slip and Fall   Motion/Pattern Recognition and Tracking   Unique face Extraction   Motion Stabilization/Frame Averaging   Noise Cancellation
 
Recording
 
Normal Mode
       

   In this mode the High Quality recording for the Camera  1  is stored into the Pre-Event Buffer (on the pre-event section of the HCS), which can hold a configurable number of seconds of integrated data stream frames. Only the Low Quality recording for a first camera and a second camera stored onto the Hard-Drive. 
   Event Mode 
   In this mode the High Quality recording for camera one is stored on the hard-drive, along with the Low Quality recording for camera  2 . The Low Quality recording for the first camera is thrown away. 
   Pre-Event Buffer 
   The Pre-Event Buffer is used only in non-event mode (Video only): in this case, two recordings for the same video source (one camera per DSP) are performed: one in low-quality (saved to the HCS), and the other in high-quality (saved into the pre-event buffer). Note that the pre-event buffer is using the HCS only, and not the memory. There is one HCS file for all video frames between 2 I-Frames, e.g. if the pre-event buffer is configured to hold 30 seconds, the record speed is set to 30 frames per second, and there is one I-frame each 30 frames, there will be 30 files for each camera input using a pre-event buffer. This method allows an easy file roll-over. 
   When an event occurs, which triggers Hi-Quality recording, the video output from the Hi-Quality camera is now saved to the HCS  730  and the pre-event buffer is prepended to the camera output to provide a configurable (from 1 to 180) number of seconds of Hi-Quality data recorded prior to the trigger event 
   HCS Buffering 
   In order to minimize the access to the HCS  730  and improve performance, a Hard-Drive buffering scheme is implemented. The following is the flow of the A/V frames, from a DSP to the HCS  730 :
         The DSP delivers the A/V compressed frames to the core_app  800  program   The A/V frames are queued into a FIFO (Shared Memory Queue  840 )   The process av_wdisk  811  reads the frames from the FIFO (Shared memory Queue  840 ) and writes them to the HCS  730 .
 
A/V Files Format
       

   The A/V files are split into two files:
         The Elementary Stream (ES), which is Audio or Video   The Frame Information.       

   The ES file is a MPEG-4 Video or Audio file. 
   The Frame Information file is a binary file, with a proprietary format, that provides:
         Frame Type (I-frame,P-frame, B-frame): one byte   Offset into the ES file: 4 bytes       

   The A/V files are stored into a sub-directory. The group of files (A/V ES files, A/V frame information files) is called batch files. To keep files with a reasonable size, a new batch file is created each 15 minutes (this is a system value configurable in the database). A new batch file is also created when the system switch from non-event mode to event mode, or from event mode to non-event mode, whether the trigger is configured or not to generate Hi-quality recording. 
   The integrated data stream files are stored in an off-vehicle storage system and follow the long term retention and review policies of each client. 
   Data Retrieval 
   Streaming 
   Live and stored streaming both use the Session Description Protocol (SDP) to describe a streaming session and all media to be viewed within that session. Streaming descriptions include elements from the core SDP standard, RTP/AVP standard, MPEG4 elementary stream standards, and custom attributes defined by the streaming server. A custom library handles SDP generation and parsing. Streaming descriptions are retrieved via HTTP. The client will request the streaming description either 1) when the user initiates playback of one or more video streams, or 2) when the MDVR discovery process determines that live streaming should be started. 
   Live streaming uses a custom RTSP-like command set over HTTP to setup, play, pause and teardown the streaming session. Video and audio elementary stream data are transported using standard RTP packets and the MDVR  100  pushes the packets to the client(s) as live content becomes available. 
   Stored streaming uses HTTP to transport video and audio frames. The client pulls frames as needed from the MDVR  100  using custom URL queries and HTTP headers. 
   Streaming Server 
   The streaming description and control interfaces use the same HTTP server framework as device manager, allowing the streaming server to leverage the same encryption and authentication mechanisms as well. It takes advantage of database and file system access routines from device manager in order to generate session descriptions and send back stored frame data. The streaming server implements custom handlers within the HTTP server framework for each of the required control and data requests. The live streaming transport  822  runs as a separate task that receives recently encoded video and audio frames from the DSP task. Based on the status of client connections, this task packages relevant frame data into RTP packets and sends those packets out to waiting clients. A custom library handles packaging and sending RTP packets. 
   Docking 
   The HCS  730  located within the mass transit vehicle will require downloading when it is full. One method for retrieving the integrated data stream files from the HCS  730  and freeing the storage on the HCS  730  for further use is known as ‘docking’. Docking the HCS  730  is to physically remove the HCS  730  from its cradle within the mass transit vehicle and place the HCS into a similar cradle attached to an off-vehicle storage server. The server then retrieves all of the stored data from the HCS by downloading it into the off-vehicle storage. 
   For retrieval of video and audio frames and per-frame information to an off-vehicle storage server, docking relies on the streaming server and uses the same HTTP requests as the streaming client in order to transfer all or part of an elementary stream. 
   J1708/J1939 
   The J1708/J1939 serves as a general-purpose serial data communication interface for vehicle telemetry. The software interface will give the host application the ability to listen to several stand alone modules attached to the serial chain. In a typical J1708 interface, the J1708 protocol serves primarily as the physical and media access functionality. SAE J1587 provides application layer functionality. As defined in the SAE J1708 spec, the software interface will be able to interpret messages matching the 1708 defined format listed below: 
   J1708 Message 
   
       
       
         
           Message Identification Character (MID) 
           Data Characters 
           Checksum 
         
       
     
  
   The software will also have the ability to handle message type defined by both SAE J1708 (MID&#39;s 0-127) and application messages defined by SAE J1587 (MID&#39;s 128-255). 
   AVL 
   AVL stands for Automatic Vehicle Location which is a term used for naming a system able to track vehicles, vessels, and mobile assets such as trailers, containers, and equipment, plot their coordinates into one or more computer generated maps and be able to interact with them in several ways. The TransitCam platform will have an AVL interface available to it as a customer option. The AVL interface will attach to the TransitCam via one of the available interfaces; Ethernet, J1708, USB, RS-232 or RS 485. 
   Log/Audit/Alert 
   There are three kinds of log information: 
   
       
       
         
           System log:
           The System Log collects log information from the kernel and various system applications and is useful to troubleshoot any system related issue. This log file is stored onto the hard-drive in a text file format. As many as the last seven days of system log are saved based upon the desired level of data to be saved, which is configurable by the user from one to seven days.   
         
           Application Debug Log:
           This log collects logging information from the TransitCAM application  821  and only intended for the development team to troubleshoot any issue. This log file is saved with the System log file.   
         
           Application Log
           The Application Log collects log information from the TransitCAM application  821 . This log file is stored on the HCS  730 , in a SQLite database format. Different types of information are logged:
               Error and unexpected events   Events triggering an alarm   All Operations such as:
                   Configurations Changes   Playback (streaming) Audit   Docking Audit   A/V files export   
                   
               
         
         
       
     
  
   If the HCS  730  is not available, no logging information is then saved, until the HCS  730  becomes available. But 128 K of memory is used to buffer (FIFO) the log messages and this buffer will be flushed to the HCS  730  when it becomes available. 
   Diagnostics 
   The diagnostics utility has a broad overall description and purpose. In the very basic sense, one could run diagnostics to simply give information on the current state of some piece of architecture. In this case, however, the diagnostics package is expanded to include utilities for manufacturing tests, in-service tests and initial power-on tests. 
   The diagnostics description is divided into two major sections. The first describes differences between different levels of diagnostics, and their implications and dependencies to the system. The second lists the various targets of the diagnostics utility. 
   Test Levels 
   Manufacturing Diagnostics 
   Manufacturing tests are by far the most destructive tests to a usable environment. This is not to say that a device will be left completely unusable. Instead, it should be specifically noted that the end user should not expect a system to keep any personalization if this level of tests are performed. The manufacturing tests should restore a usable system to a default state. This includes initial HCS  730  configuration and initial image loading into flash. 
   Local/Off-Line Diagnostics 
   This level has the opportunity to be destructive, as the test implies that a unit has been returned by an end customer because of some sort of problem. In that sense, the end user cannot be guaranteed that user specifications will be saved. Therefore, these tests may not be as destructive as Manufacturing tests, but there is no guarantee that there will not be significant changes. 
   Remote/Off-Line Diagnostics 
   For any remote tests, it is assumed that the end user personalization will not be changed. However, this test set is in general a superset of remote on-line diagnostics. This means that while user data will not be lost, a user would have a more-complete test if they return their system to a very basic state. For example, if a user needs to run HCS tests, then it is recommended the user remove any saved data streams. This will allow for more areas of the disk to be tested, extending the test coverage. 
   Remote/On-Line Diagnostics 
   This level is a set of tests that are kept very short, in order to look for basic system state while the device is in use. This level, along with POST, is run in the background to look for errors in the system. These tests are not destructive, and the user should not be concerned with configuring their device in any specific way. 
   Power-On Self Test 
   In general, the Power-On Self Test (POST) is written to be a very short and basic test of the system each time the system is initialized. The end user will most likely always prefer a system that starts as fast as possible to avoid needless delays. 
   Power On Self Test (POST) 
   The main idea behind POST is to provide a working system to the main operating system. This is analogous to the BIOS test in a PC. Each step in the POST has a different path to take based on the result of the test. The details for each test are given in this section. 
   Configuration 
   POST must be configurable with three test options are available: No-Test, Quick-Test and Full-Test. The No-Test option tests ONLY the communication between the PSP  501  and GPP  101 , as this must be verified on each power-on to ensure the very basic communication path between the two boards. The Quick-Test performs a limited test of each of the applicable components of the boards. The Full-Test is a superset of the Quick-Test, in that some components will be tested exactly the same for both tests, but will also include a higher grade of test for other components. 
   Each of the test images has responsibilities to complete certain portions of POST. This is due to the requirements of each image. 
   FPGA Unit 
   The Field Programmable Gate Array (FPGA) unit is used within the system to provide maintenance and elemental level of control for devices within the TransitCAM system. The FPGA is connected to the primary data bus and interfaces with the primary processor to issue commands for device control, such as switching views between cameras, synchronization of timing for integration of audio, video, and data streams, and providing ad hoc maintenance access for technical and maintenance crews. This unit is field programmable and field upgradable and may be used to monitor and modify primary level commands within the TransitCAM system. 
   Interface with Device Manager/Core Application 
   The diagnostics application is responsible for running tests, logging results and updating the database with those results. 
   The Device Manager (DM) will write to the database and instruct the Core Application to rescan the database to start a specific diagnostic. The DM will monitor the database for status and results (as given by the diagnostics application). 
   The Core Application  800  sends a command to the diagnostics application to start a specific test. 
   It is assumed that when a user wishes to run a diagnostic, the DM disables critical operations that could possibly invalidate a diagnostic, or which a diagnostic could corrupt data that would otherwise be considered valid. 
   Flash Database 
   As a means of communicating between the diagnostics utility and the DM, a common flash interface is used. The DM tells the core application to rescan a certain section of the database when specific operations are desired. As an extension, when a user wishes to run a specific diagnostic, they select an operation in the DM, which then changes a database value. The core application  800  then reads the database, and sends a command to the diagnostics daemon. This daemon is then responsible for either running the test, or sending a message to the PSP  501 . 
   External Control Description 
   A single external control is required. This control should be a push button located on the front panel. The push button will be used to notify the system that a device plugged into the front panel USB port is about to be removed. The system will gracefully close any connection to the front panel USB port. 
   External Indicator Description 
   Four external bi-color LEDs will be provided on the front panel. These LEDs are capable of displaying three colors: Red, Green, and Yellow (Red+Green). The following sections describe the meaning and indication of each LED. 
   LED#1, Self-Tests 
   The first LED will be labeled ‘Power’. It will be used to indicate the progress of the system during boot up and to indicate any power on self test (POST) failures. 
   LED#2, MDVR Hardware 
   The second LED will be labeled ‘Status’. It will be used to indicate the system status once the system if fully booted. 
   LED#3, Wi-Fi Network 
   The third LED will be labeled with a small antenna with three arcs emanating to the right of it. It will be used to indicate the status of the wireless network connection. 
   LED#4, Front USB Port 
   The fourth LED will be labeled with be the universal USB symbol. It will be used to indicate the status of the front panel USB connection. 
   While this invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.