- Sep 25, 2013
Photograph by jcheek
I've created this thread to discuss cell towers/base stations, an overlooked aspect of mobile broadband that is not well understood by most. Some people understand how a WiFi router works in our homes (overly simple but comparable) but how do cell towers work?
With the current mobile data explosion (specifically LTE), a lot of us may try and improve our signal levels with the aid of antennas. With an outdoor (directional) antenna, one needs to identify an appropriate base station and not everyone knows what to look for.
This new section isn't the be-all and end-all without any mistakes. It would be greatly appreciated if any industry players/experts (strictly anonymous contributions) could visit from time-to-time and help with course corrections.
Kicking things off:
Popular base station/cell tower locations:
- Schools (pre-schools, primary and high schools)
- Church grounds
- Shopping centres
- Petrol (service) stations, especially Total
- MTN (often host Telkom Mobile and Cell C equipment)
- Telkom Mobile
- Cell C (often outsourced to ATC)
- ATC (can cater for all of the above)
- Neotel (shares infrastructure with the Big 4)
Types of cells
- Macrocell (the great outdoors, large multi-tier towers; most sites are macro)
- Microcell (malls; also called minicell)
- Picocell (indoors, typically enterprise; also for outdoor hotspots)
- Femtocell (indoors, home use; ADSL/fibre backhaul; not used in SA yet, sadly)
Base station key features:
(Please help me establish who manufactures and supplies these?)
- Line-of-sight shrouded and unshrouded microwave dishes (parabolic dish, usually 1-2 on the tower)
- GSM sector antennas (elongated panels, 900/1800MHz, usually located lower down on the tower)
- LTE sector antennas (short panels, 1800-2300MHz, usually located at the top of the tower)
- Remote Radio Units (RRU bolted to the rear of a sector antenna); also called Remote Radio Heads (RRH)
- Tower Mounted Amplifiers (TMA) or Mast Head Amplifiers (MHA)
[Manufacturers: Powerwave Technologies, Alcatel-Lucent, Panasonic, Samsung, Ericsson, Huawei]
- RF Combiner/Splitter
- WiMax antennas (Neotel, iBurst, Telkom)
- WISP antennas (BitCo)
Edit: not sure on identifying antennas yet so please post a correction if you have inside info?
Purpose of each piece of equipment
- A microwave dish can either be for backhaul (up to 1Gbps) or to feed other nearby cells
- GSM antennas provide 2G or 3G
- LTE antennas provide next-gen LTE
- The RRU or RRH connects to the BTS on the ground via a fibre/power "Hybriflex" cable and relays signal via an antenna
- The TMA or MHA is able to receive and amplify weaker signals (two-way communications, send/receive) from the User Equipment (UE); it is also used when the cables between the antenna and receiver are too long or too thin
- The RF Combiner/Splitter boosts the signal going up to the antenna in the absence of an RRU or TMA
What makes up the rest of the cell tower:
- Cable clamps and accessories
- Earthing systems
- Insulation and weatherproofing
- Coaxial connectors
- Jumper cables
- Coaxial cables
- Aviation warning lights
- Cable ladders
- Steel palisade fencing
- BTS shelters (Poynting do the new-age subterranean BTS, CPS Technologies do the Cell C outdoor enclosures)
- Cellular towers (yes, the whole structure!)
Manufacturers: AlanDick, Amphenol Jaybeam, Rohn.
All aspects of power supply and backhaul still need to be detailed...
Punch in *3001#12345#* on the Keypad to enter Field Test mode. Go to GSM Cell Environment > GSM Cell Info > GSM Serving Cell > Cell ID.
Go to Settings > About or About > Network Info.
As a secondary discussion topic, please post photos of your local base stations with Cell ID and name (if possible). Not all base stations are easily identifiable e.g. roof-top cell towers look nothing like their ground cousins, while freeway/rural cell towers look like candy-stripe poles with forked omni antennas. Let's label these suckers and demystify their presence.
Cell tower backhaul
Antenna installation and alignment
How to improve your wireless experience
Telkom 100Mbps LTE rollout areas - new details
Telkom Mobile LTE Milestone
Telkom Mobile LTE 90Mbps peak speeds
Vodacom launches LTE in South Africa
MTN LTE network plans revealed
Cell C's LTE plans
How cell towers work (Gizmodo)
Installation perspective - pretty cool (YouTube 720p video of a LTE install on a scary high tower)
Sprint 4G Rollout Updates Forum (This is going to be a very sweet resource)
A special shout out to the members of S4GRU forums for sharing their knowledge.