Building a safe, open, and responsible 4G/LTE infrastructure with RuggedPOD: The Open Tower project
While being an Open Hardware project the team emphasis on building energy efficient equipments, which are safe, easy to maintain and built to last.
It shares one goal, providing a cost effective, high-speed reliable Internet access to its end users wherever they are on the planet.
Built on top of 4G, the project is facing major challenges:
- Addressing needs of variable population density area
- Addressing RF Signal health concerns and infrastructure acceptance
- Provide a good Internet user experience with low speed or costly backhaul solution.
Open Tower infrastructure is based on four core components:
- RuggedPOD outdoor computing chassis.
- 4G/LTE Amplifiers from AW2S a proprietary low cost amplifier solution as an initial solution.
- 4G software stack from Amarisoft.
- Antennas available from the market, with tested Amphenol solution.
The proprietary solutions are used for development purpose of the project. Other proprietary vendors or open source project are more than welcome to contact the OpenTower projects team for integration and qualification.
Based on these building blocks various kits are designed depending on user needs to create the mesh nodes needed to build a reliable network:
- Macro Cells in countryside and for backhaul connection
- Small Cells in residential area
- Micro Cells in shopping mall, or ultra dense area
Backhaul is the connection of the 4G mesh to the Internet. In places where high speed fiber connections are not available satellite is closed to be the only one viable option. Unfortunately standard satellite system solution requires Antennas, tracking system and bandwidth capability setup which can cost a couple of hundred thousands US dollars to setup. An additional monthly Mbp/s cost of about 400 to 800 US$ depending on volume capacity acquisition needs to be added to operate the network. Download/Upload is mostly split around ¾ and ¼ approach.
Based on these parameters, only a few Cell towers can be connected to the backhaul service within a mesh as to lower global cost of deployment. These cell towers are critical to the service and must distribute the Internet connection to smaller cells.
Cell Tower for Macro cells
Macro cells are long distance 4G coverage solutions. They support up to 3 sectors or more depending on bandwidth requirement. With the proper amplifier setup a macro cell tower can cover a circle with a radius of 30 km (depending on landscape and building density), and distribute backhaul services to smaller towers, which might relay local network needs. Macro cell towers are tall solution (between 20 m to 50 m) or must stand at highest altitude possible to deliver signal to long distance.
Targeting emerging countries where labor cost is low, raw material availability complex, and where metal have a high value and is mostly stolen, the OpenTower project is focusing its efforts on building Macro Cell site based on concrete, a widely available raw material with a very long lifespan, which doesn’t requires maintenance, and provide better energy footprint than any other material.
The architecture of the tower is based on a cylindrical core, to which a spiral staircase is attached and used to sustain external vertical beams assembly. Even if the project is targeting concrete for reliability, such construction might be produced using wood, or other alternate material like steel.
Due to the high cost of bandwidth, local storage is deployed into the Macro cell infrastructure as to cache unencrypted Internet traffic, and preload local content based on traffic big data analysis to lower as much as possible backhaul traffic.
The OpenTower Macro cell v1 supports
- 1 RuggedPOD system with 2 x86 ATX motherboard and 60 TB of local storage
- x3 20W RF 4G Amplifier
- x3 MIMO single sector 120 degres Antenna
- All equipments are integrated on a platform and setup at the top of the tower.
- Up to 24m tall
Building roofs deployment kit for Small Cells
Small cells are providing local access to residential area. With a global bandwidth of 450 Mbp/s available in a 3 sector configurations, they can cover areas of 2 to 5 km circles. The OpenTower project is working on setting up such equipments on tallest building roof with a ready to deploy kit without any pre-setup constraints other than providing power. The base station is based on RuggedPOD, which requires a very low footprint, and is lightweight. The platform used for the Macrocell version can be reused and ease the installation, setup and maintenance of the solution.
Small cell will use the same RuggedPOD version than Macrocell and can provide local Internet caching to improve end user experience. Amplifier power for such solution is about 5W RF per sector.
Attachment kit to city furniture for Micro Cells.
Micro Cells are deployed in Ultra dense vicinity and uses 500mW amplifiers to cover areas of 500 m circle. They won’t be equipped with local caching and provides connection to backhaul through Small Cells. They include an ultra dense x86 motherboard to reduce their footprint and have an attachment system to city furniture like street light poles. They require a specific RuggedPOD version, with integrated Amplifiers to facilitate deployment and acceptance, as they will be directly visible to the end user.
With a three level infrastructure the OpenTower project requires a robust remote management system. The infrastructure is based on x86 processor running advanced operating systems and software. As to lower as much as possible on site intervention, the OpenTower scalable remote management solution provides at Cell level, remote console operation, remote power on/off, reset and software deployment and provisioning as well as advanced monitoring. The solution is under active deployment under the GPL license and available on github, http://www.github.com/ruggedpod