Wednesday, July 10, 2013

Long Range WiFi on Trailer

Danielle and I have camped in a number of locations claiming to have WiFi, only to find that it impossible to connect from our camp-site due to the distance from the access point.  We have used a Verizon MiFi device in the past but we don't always have 3G data access either.  To fix the WiFi range problem, I set up a long-range wireless connection for the trailer.

In addition to better connection strength, one of my other requirements was to create a protected, local wireless network around the trailer in order to connect my astro-photography gear and the remote monitoring computer I use in the trailer.  The wireless router I used for this purpose in the past has since died so I needed to start from scratch.

I got some good starter information on putting together a system from an article by Dick Eastman. My system consists of several parts:
  • Antenna mast and cablingPortable aluminum mast from Buddipole. For the mast, I decided to use a Buddipole that I had in my ham radio gear.  It is a lightweight, aluminum, 6-section telescoping mast with the largest section 32" long and 1-1/4" diameter.  The currently available model at Buddipole collapses smaller but should work equally well.  A more inexpensive option is a telescoping painter's pole from the hardware store.
  • Outdoor antenna and wireless client deviceWLAN-LCCPE28 from L-com. The first electronic component is a single box that contains both an 8dBi antenna and a wireless network device and which mounts on the antenna mast.  It has a single wired port and is powered over the Ethernet cable by a supplied PoE box. This sort of device is typically used as consumer premise equipment (CPE) either to provide a connection to a wireless internet service provider (WISP) or to create an outdoor wireless network.  There are various vendors and models that appear to have similar functionality.  This model was inexpensive and in-stock.
  • Wireless router in the trailerTEW-731BR wireless router from TrendNet. The second electronic device is a wireless router needed to create the local wireless network for my various devices. The wireless capability of the L-com device is used only to connect to the campground network.  It does not simultaneously create such a second network.  That is, it operates either as a wireless client or a wireless access point. This is good; a wireless repeater is not the best option for this application. The router I chose to do that was an inexpensive 300Mbps model with all of the standard features.
  • Client Devices - Several laptops and iOS devices.

Hardware Installation -  The smallest section of the mast, at 3/4",  is too narrow to secure the L-com. However, the end has a 1/2" MIP threads. I purchased a couple of 1-1/2" PVC plumbing fixtures including a bushing down to 1/2" threads.  These screw in securely to the mast end.  The two PVC pieces then come apart for easy removal and storage of the L-com.



I clamped the base of the mast to the spare tire mounting post with some 4" hose clamps. When fully extended, the mast reaches about 7' above the roof line.  At that height, I will probably need to run some guy-ropes as there is flex in the mast but when only a few feet above the roof-line, it is pretty stiff.


Inside the trailer, the wireless router and the PoE box fit easily in the electronics niche above the dining table where there is a convenient AC outlet.


I plan on installing a waterproof RJ-45 outlet jack on the exterior of the trailer and routing the internal Ethernet out of sight.  I will update the post when that is completed. For now, I am routing the cable in through the window in the top rear bunk.


Configure Outdoor CPE AP Client - I followed the included instructions to make an initial, wired connection on the default address, 192.168.1.1. I then reconfigured the device per the screenshots below.

This screen configures the basic settings of the device.  The Device Name is basically the host name on the network. The name I chose, muddypaws-cpe, reminds me that this is the CPE device. Since we own Labrador retrievers, it is easy to guess how we arrived at that name!

The Network Mode is should be set to Router. The alternative, bridge mode, is not appropriate for this application. In router mode, a separate subnet is created though only the wireless router will be connected to it.  This approach allows for a well-defined IP address to access these configuration webpages again regardless of the IP issued to the device by the campground servers.


This page is a bit more involved and is were I configured the network settings.  The WAN Access Type specifies how the device will acquire an IP address from the campground.  Most public hotspots use dynamic IPs, so I set this to DHCP Client.  The host name was automatically filled in from the previous screen.

Having set up the device as a router, I needed to define the parameters of the LAN subnet.  The IP Address is the address of the device on the LAN subnet. The value 192.168.131.254, in combination with the Subnet Mask value of 255.255.255.0, defines the allowable IP address on this subnet. This is also the default gateway for other devices on the LAN. I retained the default non-routable address space of 192.168.x.x but changed to the 192.168.131.x subnet to fit in with my other networks.  I use 254 as the default gateway address on all of my networks.

The remainder of the settings define how this device will issue IP addresses to its LAN clients.  I enabled DHCP on the LAN to simplify direct connection of a laptop for troubleshooting.


On this screen, I configure how the device will interact with the wireless network.  The Wireless Mode must be set to Wireless Client. The terminology varies across vendors; sometimes this is called AP Client. This setting means that someone else has created the hotspot and this device is connecting to it.  If the campground were using the same device, they would set their mode to Access Point.

In client mode, the SSID is the network name of the campground.  In the screenshot, I was testing against my home network called plumerpack.  I did not enter this identifier directly. Rather, I pressed Site Survey to display available networks and, when I selected one, the SSID was filled in.


On some devices, selection of a network from the site survey will automatically bring up another screen to enter the security settings.  On the L-com device, this information is entered manually as a "profile".  On this screen, I created a profile with an SSID matching that returned from the site survey.  I then entered the necessary security settings for my home network.

The site survey and profile definition will need to be redone at each campground.

The two most important configuration settings for the device were:
  • It needed to be configured as a wireless client.  
  • It needed to be configured in router mode.  
Once all of these configuration changes are made I rebooted the device and tested access to the internet through my home network.

In order to re-access the configuration webpages for the L-com, I can simply browse to http://192.168.131.254 or http://muddypaws-cpe from a computer connected either directly to the LAN Ethernet port of the L-com or to the LAN of the wireless router that is described in the next section.



Configure Wireless Router - The WAN port of this router is connected to the LAN port of the L-com on subnet 192.168.131.x.  In turn, all of the computer devices connect to the LAN network of the router on the separate subnet 192.168.130.x.

Configuration is much like any other home router installation.

In this first screen, I configured the LAN settings for the router.  The Host Name of muddypaws-rtr, is distinct from that of the L-com and reminds me that this is the router.

The IP Address of 192.168.130.254 and Subnet Mask of 255.255.255.0 follow my naming convention but define the distinct "130" subnet.

On this LAN, it is important to enable and configure the DHCP Server as this is were all of the computers and devices will connect.  As on my other networks, I reserve the nodes 100-200 for DHCP clients.

I used this screen to define how the router will connect to the L-com.  For the Connection Type, I used the setting DHCP Client or Fixed IP and then for WAN IP, I chose Obtain IP Automatically to get an IP address dynamically from the L-com's DHCP Server. I could also have specified any static IP address in the "130" subnet and set the default gateway to 192.168.131.254 but I was not sure what to choose for DNS servers and maintain for portability.

On this screen, I configured the security settings for the wireless network on the LAN that the computers and iOS devices will connect to.  This is not intended to be an open network. I have used WPA-PSK TKIP successfully with all of my devices on the home network so I stuck with those settings.

Finally, on this screen I configured the settings for the wireless radio on the router.  The SSID value of muddypaws is the network name for my trailer network.

The rest of the settings depend on the type of devices which need to be connected to the network.  In this case, I chose a mixed mode b/g and n.
With this second set of configurations completed, I rebooted both devices.

In order to re-access the configuration webpages of the router at any time, I can simply browse to http://192.168.130.254 or http://muddypaws-rtr from a computer connected to the LAN of the wireless router.


Configure Client Devices - As with the home network, all of our devices work with dynamic IP addresses.  On the Windows computers, the TCP/IP properties are configured as in the following screen. The security credentials are prompted for when I make the wireless connection and then cached in a profile. The iPhones and iPads have corresponding configuration.


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