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General Overview of the Sentry MDU Technology

Introduction to the Sentry MDU System
The Sentry MDU (Multi-Data Unit) is a system that enables real-time communications, video monitoring and GPS tracking of people, places and things. We have developed software that turns a standard smartphone into a versatile multi-purpose device. It can become a “dash camera” for your car, or a high performance “body cam”, a Drone/UAV camera, a covert videorecorder, a GPS tracker and more. Of course, when the Sentry MDU App is not running, the cell phone is still just a cell phone.

The smartphones of today, are essentially small computers loaded with sensors. They are excellent mobile platforms for a variety of portable and covert applications. The Sentry MDU System has taken advantage of the fact that smartphone manufacturers have spent millions to produce existing phones with specifications that far outperform existing body worn cameras on the market. Simply install the Sentry MDU software on your smartphone, configure User permissions/access rights on the Data Server and you are ready to go.

Important Note for Law Enforcement:
  • Patrol Officers and those USING the Sentry MDU Body-Worn Camera features for official police business
    • In situations where Law Enforcement personnel are using the Sentry MDU enabled
      cell phones as “body-worn cameras” we recommend that those cell phones are
      purchased by the Department and are an “issued” piece of police department
      equipment that will be used by the Officer. This maintains the chain of custody of
      evidence for data on the device. The phones are NOT the personal property of the officer.
  • All other Police Department employees
    • The Sentry MDU App should be made available to all other employees on a
      volunteer basis. The Sentry MDU App is available for FREE from the DLT
      Website and can be installed on the employees personal cell phone just as
      if they installed an App from their Credit Union, Bank or Employers Website.
      The Sentry MDU App simply allows them additional access to other employees
      and Officers in the field using a mobile device.

One of the features of the Sentry MDU System is the ability to have “another person” (or several people) access the device you are wearing (with your permission of course). They will be able to see what you see and hear what you hear in “real-time” just as if they were standing behind you.

How many times have you walked onto a scene and realized it would be very helpful to not only “record” what is going on (traditional Body Cam), but have another pair of eyes looking at the scene with you? No longer are you by yourself, all alone out there. You can have your support team watch and listen to what is going on around you.

Whether you are a Real-Estate Agent meeting someone at a house for a showing, a car salesman out for a ride with a potential buyer, a cashier at a Convenience Store, or a police officer stopping someone late a night on a lonely stretch of road, it may be comforting to know that you can have other people aware of your situation.


Hardware and Software components of the Sentry MDU System
The Sentry MDU System is a 3 tier communications and GPS tracking system that is optimized to run on either Cellular or WiFi networks (when coverage is available). In areas of no cellular coverage, the Sentry MDU device automatically reverts to “standalone” mode. The Sentry MDU System is typically referred to as a Client-Server implementation.

The system incorporates three distinct layers of technology
  1. A portable (or mobile) platform which is typically a smartphone (cell phone) or Tablet device.
  2. A Desktop Computer that runs a software “Client” that provides a gateway to the central Data Server.
  3. A high performance Data Server that provides the primary internet connection, mapping capability and secure data storage.

The hardware components within the three layers are as follows:
  1. Mobile Device - Cell phones, Tablets or other devices that use the Android operating system.
  2. Desktop Computer - (or laptop) running the Microsoft Windows operating system (Win 7, 8, 10).
  3. Data Server - Typically this should be a high performance, secure, rack mount server with 24/7/365 reliability. The Server will run the Microsoft Windows operating system and should be configured with redundant data storage, redundant power supplies, operating on a UPS system and administered by the local IT Department.
  4. Editorial Note: For those organizations that do NOT have the in-house capability to design, configure and/or operate the Data Server, Digi-Lumen Technologies can provide assistance as necessary.

Sentry MDU System software provided by Digi-Lumen Technologies:
  1. For Mobile Device - Sentry MDU smartphone App, available on the DLT Website.
  2. For Desktop Client - Sentry MDU Client Application (Users may elect to have one or more Desktop Clients)
  3. For Data Server - Sentry MDU Server Application (only one Data Server license is required per organization)
  4. Editorial Note: For those organizations that do NOT wish to host their own server instance. Digi-Lumen Technologies offers a variety of hosting plans and/or can provide assistance as necessary.

The Data Server component of the Sentry MDU System is scalable to tens-of-thousands of users. In reality, thousands of users per instance may be more realistic. The primary limitation for large users will be the available internet bandwidth that the Customer has purchased from their internet provider and the policy guidelines that the organization has established on “when” real-time audio/video should be streamed from the remote device to other users on the network.

The following picture shows a typical NETWORK CONFIGURATION of a Sentry MDU installation.


Features of the Sentry MDU System
The Sentry MDU System starts with a cell phone (smartphone) or Tablet device. The only requirement of the Sentry System is that the mobile device uses Android OS Version 5.1+. In practical terms any Android cell phone manufactured within the last few years should work just fine. Obviously, newer cell phones will have higher performance than older devices.

In the Features discussion shown below, we are using a Samsung Galaxy Smartphone as the device “platform”. The device is installed in one of the many, readily available waterproof cases.

Generally, all Body Worn Cameras are about the same. Certainly there are minor differences in size, location of controls, field of view and so on ... but for the most part, all of them will function well as Body Worn Cameras. For those organizations that want the comfort of a single purpose device we feel that any Body Worn Camera will work for you.

However, for those departments that would like something more robust, a further leap in technology, we would suggest that the Sentry MDU (Multi-Data Unit) System will provide you considerably MORE Capability, Usability and Deployability at a significant cost savings.

Typically, in a website section on FEATURES, we would provide a Comparison Matrix of Sentry MDU Features to the competition. To save time, we will simply state that using any quality smartphone device as a “platform” and running the Sentry MDU App software ... our devices meet or exceed the competition in almost every category that is measured.

The chart below will focus on those aspects of the Sentry MDU System that are generally NOT offered by your typical Body Camera. The Sentry MDU system is NOT a single purpose body worn camera. It is a fully integrated communication device that happens to use a cell phone platform as the hardware.

To illustrate, a few specifications are selected to make the point:

Specification Sentry MDU System Group of 7 Body Camera Suppliers
Hardware Design and Availability The Sentry MDU software suite turns a standard cell phone (Smartphone or Tablet) into a multi-purpose device. These are “standard” off-the-shelf items purchased at any local cell phone store. The Sentry MDU System has taken advantage of the fact that smartphone manufacturers have spent millions to produce existing phones with specifications that far outperform existing body cameras on the market. Proprietary single purpose device.
MSRP of Device Digi-Lumen Technologies does NOT sell hardware. Agencies will need to purchase cell phones from their local Cellular Store. Prices can vary from $200 - $800 USD each. For other department personnel that volunteer to install the Sentry MDU App on personal cell phones ... there would be no cost for the device. The Sentry MDU “App” is just one more “free” Program App on the phone. For Body-Worn Camera devices, with accessories, prices range from $600 - $1,100 USD depending on the model and manufacturer.
Cost of the 4G-LTE (5G) Cellular Data Plan for the device To take advantage of real-time audio/video from almost anywhere a department will pay for a cellular data plan for those cell phones that are to be used as Body-Worn Camera devices. They should expect to pay about $50/mon USD each. 4G-LTE (5G) is not available, therefore, there is no cost for cellular service.
Software Cost We LICENSE the software that makes the Sentry MDU system work. We have three sets of software that are outlined above. We have pricing plans for groups of 5 to 5000. Some suppliers bundle software with their cameras while others it is separate.
Min and Max video resolution Can be anything the user wants to use. User can set framerate (5fps - 30fps+), video resolution (ie 360x180, 480x240, 640x480, 1280x720, 1920x1080 and so on), bitrate of the transmission upload and more. User also a choice of formats such as h264, h263, mpeg4, 3gp, etc. Depends on manufacturer. Minimums are 640x480 - 848x480 and maximums are 640x480 - 1920x1080.
Onboard Storage Can be anything the user wants to use that is available for the device. Current models have 32GB to 128GB storage available + up to 256GB of SD-Card storage. However, the Sentry MDU device can automatically upload content via 4G-LTE cellular networks (or 5G, WiFi) during scheduled intervals (set by User). Most manufacturers offer from 8GB up to 64GB capacity.
Video streaming The Sentry MDU offers real-time video streaming from the device via 4G-LTE networks (or 5G, Wifi if available). The video stream can be shared with other Officers on their device (as “live” video) and can be stored on the local device SD-Card or transferred to the central Data Server for future analysis. Not offered as standard option.
Ability to share GPS location data with other Officers Depending on department policy the device can be configured to provide the GPS location of all Officers that are currently on duty. An Officer will be able to view a satellite image map and see the real-time location of all other officers. The ability of a user to zoom down to street level is also available. This is beneficial when officers are on foot, chasing a suspect or doing a search and need to know where other officers are located. This feature is not available.
Monitor and record environmental sensors Cell phones are equipped with a variety of environmental sensors. These include barometric pressure, light sensor, GPS location, acceleration, magnetic field, motion sensor, battery voltage, cellular signal strength and more. All of these sensors can be recorded on the device and remotely monitored by the Command Center and/or other Officers (provided adequate security permissions are granted). Alarm points can be set for all sensor data. This feature is not available.
GPS integration with Audio and Video recording GPS is one of the sensors available to the user. Video or audio playback can be synced with GPS locations on a satellite map image. These are available on the device screen for playback in a split-screen view (video playing while GPS track moves on a map). Historical data can be pulled from the Data Server back to the mobile device for playback as necessary. About half the suppliers offer GPS as an OPTIONAL feature but none with on-device mapping capability.
Covert and Remote Access to the Device The Sentry MDU System can operate in “stealth” mode such that the device can be controlled remotely. Audio and video recording can be turned on-off from the Command Center and/or from other Officers devices as security permissions allow. This will enable the device (cell phone) to be used as a mobile “real-time” surveillance camera that can be placed anywhere. This feature is not available.
Methods to start-stop a recording session Activating the Audio/Video recorder on the Sentry MDU System can be done by a number of methods.
  1. Manually start recording by clicking on a screen button.
  2. Tap Control. We use the motion sensing capability of the cell phone to respond to a series of “tap commands”. Two taps to turn recording on and three taps to turn off. The user may adjust the sensitivity of the required “tap” from very light to very hard.
  3. Voice Activation. The Sentry MDU device has a voice activation feature where a user can start and stop recording by talking to the device. Voice activation is mostly used for “dash cam” applications where the device is mounted on the Patrol Car windshield and the on-off buttons are not as readily accessible.
  4. Combined Activation Methods. In the options above a User has the ability to start recording with a “tap command” but terminate the recording “manually”. This is most often used where an Officer would drive up on a situation (ie domestic abuse call) and get out of the Patrol Car, activate recording with a “tap command” but want a manual “stop”. In the event things get rough he would not want the Body Cam to stop recording if his movement (restraining someone) was interpreted by the software as a “turn-off tap command”.
Existing devices generally have a button that must be pressed to activate the device.
High Resolution Camera Typically a cellphone will have a 12 - 20Mpixel camera to take high resolution images. Obviously, pictures can be taken with the native cell phone camera. However, Sentry MDU has additional camera features within the App that allow a User to take pictures and then edit them by drawing or writing on the image to identify parts of the picture that are of interest. These pictures may then be sent to any other Sentry MDU user on the network. This feature is not available.
Internet Search and Bookmarking Capability Sentry MDU has the ability to “bookmark” other users on the network, specific websites of interest, and specific content and places of interest on satellite view maps for easy retrieval. This feature is not available.
Internal “text messaging” feature Sentry MDU has a built-in text messaging feature that allow users to send text messages to one another (separate from the cell phone text messaging function). These texts may contain pictures and “hand drawn” messages by using your finger as a pen stylist. The texting function is routed through the Sentry MDU Data Server and not the cell phone carriers system. This feature is not available.
Share CONTENT with other Users on the network A User on the Sentry MDU System has the ability to share any content (pictures, maps, videos, etc.) they have on their device with any other user on the system (assuming permissions have been allowed during User configuration). This will allow an Officer that took a picture of a suspect to immediately make this image available to other users on the system. This feature is not available.
Data Encryption Capability The Sentry MDU System has the ability to transmit data either encrypted (SSL) or unencrypted. The decision on which to use depends on the IT policies of the user and the sensitivity of the data. This feature is not available.
Automated UPLOAD of data from the device to the Data Server The Sentry MDU System can transfer data from the device to the central Data Server by a number of methods.
  1. Automated upload via WiFi. The device has the ability to schedule uploads at certain times of the day. For example, at the end of an Officers shift it could be scheduled such that as he walks into the Station, the device automatically connects to the data server via WiFi and transfers all designated data from the device to the central Data Server. No action is required on the part of the Officer. It all takes place automatically.
  2. Automated upload via 4G-LTE (5G) cellular network. Like the Wifi scenario, the device can be configured to upload all content on a particular schedule each day. No action is required on the part of the Officer. It all takes place automatically.
  3. If “real-time” data streaming has been used, then the recorded information (audio, video, environmental sensors, etc.) has already been uploaded to the Data Server and no action is required.
  4. User initiate a data transfer. A User has the option to record audio/video (not in streaming mode) and then transfer the video manually (via Wifi or 4G-LTE) to the Data Server. This would most often be used when the Sentry MDU Device is being used as a “dash cam” in a Patrol Car and there is no need to perform data streaming.
  5. Manual Transfer. A final method is to use a USB cable and transfer any data from the device to the central Data Server. However, this method is almost never used.
This feature is not available. Current devices generally require a connection to a docking station or USB cable to transfer data.
Display screen for playback Typically a cell phone will have a 4 to 5 inch AMOLED high resolution screen. Half of the suppliers offer 2.0-inch LCD screens the others do not offer a screen.
Record Audio Only The device can record Audio only. Users can configure audio sampling rate and transmission bitrate for use during real-time audio streaming. In addition, the device can be “remotely” activated to record both audio and/or video. It can become a remote activated covert listening device. Half of the suppliers offer the Record Audio Only feature.

Feature Summary of the Sentry MDU smartphone application
  • Standard Android cell phone used as hardware platform, available everywhere
  • Cellular 4G-LTE, 5G and WiFi network coverage as needed (also standalone mode)
  • Real-time video streaming to Command Center and other users on the network
  • Remote access to device. Audio and video recording can be remotely activated.
  • 32GB, 64GB or 128GB available internal storage + 256GB SD-Card storage
  • 12 - 20Mpixel camera picture capability
  • Ability to take and “edit” pictures on the device and then send to others
  • 1080HD, 720, 640, 480 video resolution
  • 4 - 5 inch, AMOLED high resolution screen
  • GPS capability, location of other Users on satellite view maps
  • Motion Detection and Object Recognition (AI) features when used as a surveillance camera
  • Automated upload of data as scheduled by User (no docking bay required)
  • Recording activation by Tap Command, Voice, Manually and Remote User
  • Dust proof and water resistant with available cases
  • Rechargable Battery (external battery packs available)
  • Can function as Body Worn Camera, Car Dash Camera or Drone/UAV camera (with available mounts)
  • Advanced Text Messaging features (separate from cell phone messaging App)
  • Monitor Environmental Sensors
  • Content on the device can be shared with other Users via 4G-LTE and Wifi
  • Data encryption is an available feature
  • The “bookmarks” feature allows the bookmarking of online websites, other Users and Content
  • Two-way video phone capability
  • Software App updates delivered via DLT Website

Cost for the Sentry MDU System
The cost for a Sentry MDU System has several elements. We understand that every organization is different and has varying levels of computing technical expertise. The needs (and financial resources) of a small rural Fire Department may be vastly different than a major Metro Police Department. This section will outline, in general terms, those items that need to be considered when making a decision.

Questions to ask that will impact the COST of a Sentry MDU installation:
  • How many DEVICES will you want to have on the system?
  • How many DEVICES will the department purchase that will be used as body-worn cameras?
  • Will the cell phones that the Department purchases be “shared” among Officers or will they be directly assigned?
  • How many Desktop “Clients” do you need?
  • Have you identified the “data security” issues for information that will be stored on the central Data Server?
  • How many Data Server instances do you want? (generally only one is required)
  • Do you want to HOST your own dedicated Data Server instance, pay DLT to host a server, pay a third party to host a server, or purchase a spot on a “shared” server hosted by DLT?
  • Will you require on-site training for your Users?
  • Do you want to purchase on-going product support? (ie Software Maintenance Agreement)
  • Can you estimate how much “streaming video” you will use? (this sets internet usage requirements)
  • Do you have access to high bandwidth internet service? What is the cost of this service?
  • Do the anticipated Users already have cell phones that can be used as a “device” or will cell phones need to be purchased?
  • Editorial Note: For those organizations that need help in answering some of these questions, Digi-Lumen Technologies can provide assistance as necessary.

For a total project cost you will need to include any cost for devices, computers, internet bandwidth, or IT Support that may be necessary.

The Sentry Manager screen (Desktop Client)
Below is an example of the Sentry Manager display on a Desktop Computer.
  • Main Map screen of the Sentry Manager (Satellite View)
  • Shows “live” audio/video panel overlays on screen
  • Can run on a Laptop in a “mobile” Command Center

A few Sentry MDU App screen examples
Below are a few examples of the Sentry MDU display on a mobile device (cell phone/tablet).
  • Main Map screen of the Sentry MDU App
  • Playback of video history
  • Sentry MDU as an automobile dash camera
  • Sentry MDU as a tactical Drone/UAV camera
  • Image Editing Tools
  • Screen view on a 10 inch Tablet






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