Tuesday, 06 December 2011 21:13

A Firetide Video Security and Mobility Project – Part 2 Featured

Written by  Dennis Moxley
Rate this item
(0 votes)

In my first post, “A Firetide Video Security and Mobility Project,” I gave a high-level overview of the project and a brief description of some of the existing hardware. In this post, I will go over the wireless design and the new Firetide line of wireless radios used to provide backhaul, mobility and WiFi access.

The project is to provide video security as a force multiplier. In support of this main goal, the facility has chosen Firetide wireless gear to reduce deployment costs. Firetide Mesh Networks act as a virtual network switch providing connectivity less expensively than typical fiber optic cable deployments. Since the facility already has Firetide 6000 series radios in place for backhaul and mobility, we will be using these radios as well as the newer 7000 series radios. The wireless design can be broken down into three different functional groups: Wireless Mesh Backhaul, Wireless Mesh Mobility and WiFi Access. We will discuss each of these functional groups in detail.

Wireless Mesh Backhaul

In the past, analog video was transmitted from cameras to a recording device via coaxial or fiber optic cables. While this method does provide a relatively stable and high bandwidth medium, it can P2Pbe cost prohibitive or even impossible in some scenarios. Wireless backhaul simplifies the installation by eliminating the need for costly trenching and cable laying. With the mainstream acceptance of modern IP based Megapixel and HD cameras analog transmission systems are becoming less popular. Newer cameras transmit their video over standard IP based networks without the need for encoders and decoders.

What is the difference between Wireless Backhaul and Wireless Mesh Backhaul? Wireless backhaul is typically a point to point or point to multi-point configuration. A single pathway exists between remote devices and the core network. A Wireless
MeshMesh Backhaul provides multiple pathways from the remote device to the core network and in turn provides built in redundancy. Since there are multiple pathways from a remote device to the core network, a routing protocol has to be used to determine the best route for data to take between end points. This is where Firetide differentiates itself from the competition. Most wireless mesh manufacturers use a protocol such as OSPF, RIP, IGRP or EIGRP. Each of these protocols, by their nature, incurs an “overhead” of network traffic that uses up valuable wireless bandwidth and creates additional processing load on the radio. Firetide has a patented technology called AutoMesh that eliminates these issues.

“Firetide's AutoMesh™ routing protocol manages network load and traffic congestion to optimize mesh-wide performance and capacity.”

In order to comply with the NDA and other security regulations, we cannot name the client or give the geographical area of the project. Therefore, we have masked the background in Google Earth to remove geographic landmarks, but still provide a representation of the network design.

Sites

There are 37 sites where radios and or cameras will be installed. Site selection was performed using several criteria: Field of view for security cameras, line of site to other nodes, mobility coverage area and WiFi coverage area. Wireless Mesh Backhaul will primarily utilize existing Firetide HotPort 6202 Mesh nodes. These nodes have two radios that can be configured to use different frequencies / channels and power levels. (You can read more about the Firetide HP 6202 Wireless Mesh Nodes in Part 1 or at www.Firetide.com) There are 19 Backhaul locations. (The yellow lines represent existing fiber runs at the facility.)

BH

There are five connections to fiber. Firetide calls these location Network Gateway Interfaces or NGIs. A complete mesh is not possible due to channel planning restraints. Instead, we have designed a hybrid ring topology that affords most nodes redundant paths to fiber and the core network. Most vendors limit the number of “hops” to a wired network connection to four or five. Firetide can support as many as 10 hops OR MORE! This is a huge differentiator. In this design, no node is more than five hops from a fiber connection point. This is due to the proliferation of existing fiber – not a wireless design limitation.
That being said, if you have fiber – use it, if you have CAT-5/6 – use it. Do not use wireless just for the sake of wireless. You will always have a more stable connection with greater bandwidth with a physical media. The use of wireless should always be a cost/benefit evaluation.

BHLOS

The backhaul network will be used to transmit video data as well as carry the mobility and WiFi data. When designing any wireless network, you should always start with the intended applicaCamSpecstion bandwidth requirements. This will give you the foundation on which to build the design. In our case, we will be using Pelco Spectra HD Series IP Dome PTZ Cameras. These cameras are industry-leading high definition cameras. They support H.264 compression and have built in analytic features. For our calculations, we will be using the maximum resolution and frame rate values. At 1.3MPx, with 20 IPS, Pelco says we can expect a bit rate of 3Mbps. I usually add another 1.5Mbps for overhead, so we assume 4.5Mbps per camera. Assuming each site had at least two cameras operating at 4.5Mbps, we should be able to make five hops before reaching 50% of Firetide’s published throughput (70Mbps).

 

Since this is a worst-case scenario, (most cameras do not need to be recorded at 30 IPS, typically, 3-7 IPS is adequate) we should be good to go with the design. We still have 50% of the total throughput available for mobility viewing and WiFi traffic. This also gives us more flexibility to tune the network. (More on that in a later post about post installation tuning.)

BWAgg

The Mesh nodes are using 24 dBi 5.1-5.8GHz panel antennas. They can be used in a horizontal or vertical position and have a physical +/- 45˚ up or down tilting mount. The horizontal and vertical RadPatternbeam widths are 8˚, which will provide a good balance of signal strength and ease of installation. These antennas are mounted on various light poles and buildings throughout the facility. The standard mounting height is 30 to 35 feet above the ground.

Let us talk about wireless mesh design with dual radios. One of the advantages of dual radios is the ability to send and receive data at the same time. This provides a full duplex connection. If a dual radio node is used for both backhaul and mobility, the backhaul radio is handling both data transmission and receipt. The mobility radio is not a component of the backhaul at all. This changes the backhaul to a simplex connection. This is a problem for many Mesh Radio manufacturers. In addition, mesh radios that also provide WiFi access as well as backhaul face similar issues. Our design uses a dedicated two-radio node for backhaul and a separate two-radio node for mobility.

Wireless Mesh Mobility

Our design uses Firetide HotPort 7000 Series Wireless Mesh Nodes for mobility. The 7000 series nodes are the latest iteration of Firetide’s wireless mesh products. One of the key features that support our design is the addition of MIMO functionality. Wikipedia describes MIMO as:

In radio, multiple-input and multiple-output, or MIMO (commonly pronounced my-moh or me-moh), is the use of multiple antennas at both the transmitter and receiver to improve communication performance. It is one of several forms of smart antenna technology. Note that the terms input and output refer to the radio channel carrying the signal, not to the devices having antennas.
MIMO technology has attracted attention in wireless communications, because it offers significant increases in data throughput and link range without additional bandwidth, though extra transmit power is needed since multiple transmit antennas are employed instead of only one as in SISO systems. It achieves this by higher spectral efficiency (more bits per second per hertz of bandwidth) and link reliability or diversity (reduced fading). Because of these properties, MIMO is an important part of modern wireless communication standards such as IEEE 802.11n (Wifi), 4G, 3GPP Long Term Evolution, WiMAX and HSPA+.

Why is MIMO important to a mobility design? The mobility environment is constantly changing. As a vehicle transits through a node’s coverage area, it is affected by many different environmental influences, which vary the connection quality and reliability. In standard SISO systems, the vehicle passes through signals that are reflected, out of phase, nulling the signal, and around obstacles that block line of sight, reducing the signal strength. There are signal strength issues as the vehicle approaches the node and as it departs. All the while, the mobile node and static node are negotiating the best connection parameters. MIMO helps to minimize the impact of these issues. I will not go into a technical description of the pluses and minuses of MIMO in this post. There are many resources online covering that topic. Specifically for this project, MIMO is a good fit since the area we are deploying in is a constantly changing outdoor industrial environment. In fact, the very obstacles that would severely affect a SISO solution, work to enhance the MIMO capabilities.

The Firetide 7000 Series Wireless Mesh Node has the following features:

  • Convenient Upgrade Paths – You can enable the features you need for a particular deployment. Need just one radio, no problem. FTHP7000Don’t need MIMO, no problem. You get what you want (and are willing to pay for.)
  • Easier Deployment and Network Management - Unlike wired networks, where deployment is cumbersome, the self-forming nature of the Firetide mesh network ensures rapid deployment of large-scale networks. The HotPort 7000 mesh features integrated spectrum analysis, network capacity planning and antenna alignment tools for easier deployments and network management.
  • Dual-radio Performance - To maximize performance, dual-radio HotPort 7000 nodes support two radio modes. In the “bonded” mode, both radios are combined to operate as a single unit that provides double the bandwidth of a single radio equivalent. In the “linear” mode, both radios operate independently enabling sustained bandwidth levels over an unlimited number of hops. This enables long linear topologies, such as when networking a railway line, and provides a sustained level of service to every node, which is also critical for large municipal networks.
  • Quality of Service - Firetide's patented AutoMesh™ flow based routing protocol supports advanced load balancing and congestion control mechanisms for optimal routing within the mesh network. The HotPort 7000 mesh infrastructure also provides extensive VLAN capabilities critical for deploying a multi-service network on a large scale.
  • Multicast & Security - Firetide infrastructure provides reliable multicast capabilities critical for large-scale public safety and broadband access networks. Firetide mesh provides advanced security, including 802.11i support, dual-layer of FIPS140-2 certifiable 256-bitAES encryption, digital certificates on network elements, digitally signed firmware files, MAC based access control lists and VLAN based access control lists.
  • Flexible Configuration - Indoor and outdoor HotPort 7000 nodes feature dual or single configurable radios in the 2.4, 4.9 (U.S. public safety licensed band) and 5 GHz frequency ranges. HotPort 7000 mesh can utilize channel widths of 5, 10, 20 and 40 MHz (MIMO only), with 5 and 10 MHz channel widths only available on the 4.9 GHz band.
  • See Firetide’s datasheet for more technical specifications.

So what is the big deal with Wireless Mobile Mesh? Isn’t it just like wireless WiFi access in a car? Well, yes and no. It is a wireless device in a vehicle, but that is where the similarities end. Mobile Mesh extends the wireless infrastructure to the vehicle. In other words, the vehicle is PART of the MESH! This is a significant difference.
Typical mobile mesh clients are single radio devices that have to transmit/receive data with the currently connected node and negotiate connections with the next node. Firetide uses a dual radio in mobility mode. This dedicates one radio to searching for the next, best connection while leaving the other radio to handle data transmission. Once a connection is established with the next node, a seamless handoff takes place and the other radio becomes the search radio. Patented radio switching architecture that lends to efficient consumption of data packets placed in mobile queues before radio switch is performed. This feature provides zero packet loss, high speed switching in the most challenging situations. To assist in data routing, Firetide has an inherent protocol algorithm that pre-caches multiple routes from a given node to another.
Mobility nodes are placed in strategic areas required for coverage and are irrespective of backhaul locations. While several mobility sites are shared with backhaul nodes, this is not a requirement. This image depicts the mobility node deployment plan.

Mobility

The applications used over the mobility network are much less bandwidth intensive. The video viewing software receives streaming video in a much more compressed format that the video streamed from cameras to the recording device. In fact, the viewing client allows multiple streams to be viewed simultaneously with minimal network impact. The Endura Web Client limits the bandwidth utilization based on the network connection type. It can be throttled from 56Kbps to 1,000Kbps. Initially, there will be three mobility client vehicles. Each will have a Firetide 7020 Mesh Node and a Panasonic Toughbook laptop.
The Mobility Mesh Nodes will use a mix of omni directional 3x3:2 MIMO antennas and panel antennas depending on the coverage requirements. 3x3:2 MIMO Omni directional antennas are mounted above the patrol vehicle light bars.
The static Mobility Nodes that are mounted on the same poles as the backhaul nodes will plug into the Ethernet jacks of the backhaul nodes. This will provide an NGI for the Mobility Mesh.

Next time I will discuss the WiFi component and hopefully get into more design details.

Thanks for reading!

Enhanced by Zemanta
Last modified on Wednesday, 07 December 2011 13:34
Dennis Moxley

Dennis Moxley

Dennis Moxley is a leading expert in Information Technology. Over his twenty years of IT experience, he has managed IT departments for large public sector institutions as an Information Security Officer for the Department of the Navy and as IT Director for mid size healthcare companies like Evergreen Healthcare and Southwest Washington Medical Center. He has been published several times in trade magazines and holds multiple premium IT certifications such as Microsoft Certified Systems Engineer. He is very experienced in all aspects of security including physical, network and personal information protection. He has worked with law enforcement in computer forensics. Born and raised in the Northwestern United States, he is very familiar with the nuances of the silicon forest and has a vast network of contacts in various industries. Previously he was the Chief Technology Officer of a Portland based security company, 1Pointe. Currently an owner of m&m Innovations. 

Leave a comment

Make sure you enter the (*) required information where indicated.
Basic HTML code is allowed.