back to article Small cells are like DRUNKS. They don't use lamp posts for light, they use 'em for support

A new design of mobile cell site that sits on top of an existing street light has been developed British design company The Technology Partnership (TTP). Street lights are an obvious place to put mobile network infrastructure. They're erected in the places where there are lots of people and they have a power supply. While …

  1. Dave 126 Silver badge

    >Steve Baker prefers a point to multi-point microwave approach,

    I'm no expert, but I would have thought a Line Of Sight approach naturally fits lampposts, since from one lamppost you can usually see others.

    1. TRT Silver badge

      Being as the lamps form natural horizontals at around 10 metres height...

      They could used RFC1149 for the backhaul. IPoAC. Simples.

  2. TRT Silver badge

    And from the other end, there's an ongoing drive to turn street lights into connected neighbourhoods with intelligent, individually addressable lamps for the purposes of energy and infrastructure management. Two birds, one live cable touching an unearthed casing.

    1. Jimmy2Cows Silver badge

      Ongoing drive,,,

      Around here there's an ongoing drive to turn off street lights between midnight and 5 am as the council's skint.

      Hopefully that means each individual lamp is controlled so it may be switched on/off remotely without killing the power supply. Knowing how our council likes to "plan" things they probably just pull the plug at the control centre. That's the kind of thing that could kill this idea dead.

      Can't imagine residents being happy about loss of mobile signal overnight. Sure, I'd hope there'd be fallback to a larger cell, but I can easily see the cellco's removing the larger cells if they have street-light coverage. Cost savings and all that.

      1. TRT Silver badge

        Re: Ongoing drive,,,

        We had the same. A Yorkshire company made replacement photocells that worked out midnight from dawn/dusk observations, calculated the date so it could adjust to daylight saving times, then turned off from midnight to 6am, all independently of any external input in a package that could replace a standard dawn/dusk module. And a mere 6 times the price of the standard photocell.

        But they used a PIC microcontroller running some sequence they'd written which has the following "features". At the equinoxes, the controller had a divide by zero error which crashed the controller and turned the lights on during the day and off all night until the power supply was flipped at the roadside pillar. A really, really dark cloudy day, around 4pm in March or October, which shifted the dusk detection time by more than half an hour, caused the system to recalculate the date and recalibrate, meaning it failed-safe to lamp on all the time. The system has an internal battery maintained clock which never runs at the right rate.

        To correct these software bugs, they had to replace every single one of the 64,000 they'd installed throughout the county. And the new ones STILL go wrong at Equinox.

        My solution? A free-running counter, any reasonable speed would do, a photocell, a divide by two stage, a second counter connected to the divide by two stage, a latch, a comparator and a 555 delay circuit. At dusk, turn the lamp on and start the counters running at full speed and half speed. If the running counter goes above the value held in the latch that being the value of the half speed counter from the previous day at dawn, the light goes off, triggering a time delay of around 6 hours to hold the lamp off unless dawn occurs before then. The counters run on until dawn, ready for the next day.

        No microprocessors. Nothing expensive. No software to go wrong, just a true midnight, self-calibrating system. Who needs 0.1% accuracy of timing on a street light, FFS? Most appropriate solution at the best price.

        1. Mark 85 Silver badge

          Re: Ongoing drive,,,

          Sounds good... I hope you've filed a patent.

        2. Alan Brown Silver badge

          Re: Ongoing drive,,,

          "My solution? A free-running counter, any reasonable speed would do, a photocell, a divide by two stage, a second counter connected to the divide by two stage, a latch, a comparator and a 555 delay circuit"

          Still overly complex and people HATE dark streets.

          Dimming 90% and brightening up when movement is detected seems to be the way forward. Of course the "quality british designs" (meaning the idea is ok but the execution is crap) will win out thanks to "buy UK" campaigns, instead of picking what works and actually saves money.

          BTW, the electrical cost savings in turning off non-led lamps for part of the night are more than made up for by thr added labour and hardware costs caused by premature failure thanks to the things being cycled twice as often as they were originally intended to be (discharge lamps have lifecycles measured in hours OR cycles, in a similar manner to pressurised aircraft - thankfully an over-cycled lamp doesn't blow its roof off midway through the night)

          1. TRT Silver badge

            Re: Ongoing drive,,,

            How long will our stock of the minerals required for high density LEDs last? Just a general query, not implying anything.

            1. Death Boffin

              Re: Ongoing drive,,,

              Considering its mostly Silicon and Carbon with a smattering of Aluminum, Gallium and Nitrogen, quite a long time. That's GaN on SiC for those of you looking at the LED ads.

      2. P. Lee

        Re: Ongoing drive,,,

        >Around here there's an ongoing drive to turn off street lights between midnight and 5 am as the council's skint.

        As the lights are off all day, I hope they've already thought of that!

        50m Line of sight links anyone?

  3. Peter Ford


    Powerline ethernet? Might need some encryption to stop the spooks reading the bits from the flickering lamp (especiallywith new-fangled LED street lights)...

    1. Anonymous Coward
      Anonymous Coward

      Re: Backhaul

      "Powerline ethernet? "

      Discharge lamps are wideband RF emitters (just like powerline ethernet).

      The discharge lamp's emissions will render the powerline Ethernet useless.

      LED streetlamps? Don't know for sure, but I have heard lots of stories that some switched mode power supplies used with domestic LEDs emit lots of wideband RF. So same problem as discharge lamps.

  4. Simon Rockman

    I suggested flashing the light as Li-Fi, but Steve Baker thought it would be too slow. And only work at night. I think he had a point.

  5. Jimmy2Cows Silver badge


    "It’s all very well being able to get the mobile signal to the eNodeB on the street light but getting the voice or data from the lights to the phone network is a tougher problem.

    TTP kind of employs a SEP (somebody else’s problem) field solution to this, but offers a partial answer in the form of an a Gigabit interface for S1/X2 and provides Power Over Ethernet..."

    And there's the elephant in the room. It still requires digging up the roads/pavements, or persuading existing infrastructure owners to permit access to their ducting. So massive, widespread, long-term disruption with lamp post cells, instead of localised short-term disruption from building a bigger cell tower with more coverage.

    1. Steve Baker

      Re: Elephant

      This misses the fundamental point! No need to dig up pavements. Gigabit Ethernet isn't cabled all the way back to the network core :-) There's just a short cable run down to the wireless backhaul node which is clamped to the post. And power is supplied from the cell to that backhaul node using POE.

    2. This post has been deleted by its author

    3. Mike_1727

      Re: Elephant

      Small cells are (largely) used fpr capacity not coverage. You get the ectra capacity by re-using frequencies/codes much mpre pften because small cells cover...a smaller area which mavro cells can't.

      Cost is a big issue too,small cells are an order of magnitude smaller than macros.

    4. Alan Brown Silver badge

      Re: Elephant

      " localised short-term disruption from building a bigger cell tower with more coverage."

      The point about the bigger tower with more coverage is that it covers TOO MANY phones. Telcos only shrink cells when they have to. A smaller one costs just as much at the backend as a larger one.

  6. kmac499

    Pole Squatting Cells

    A neat design that could be employed in a variety of installations where you might have a sudden influx of people. Festivals, Sporting, Disasters etc.. Presumably it could also be fitted in trains coaches etc once a suitable backhaul is devised.

    1. Jess--

      Re: Pole Squatting Cells

      sounds to me like these cells should use some of their own capacity to link to their neighbour creating a daisy chain link with each cell acting as a relay for its neighbour until it reaches a cell with true backhaul

  7. Little Mouse Silver badge

    “like a hamster eating its own babies”

    I thought I'd heard every IT analogy under the sun.

    Turns out I was wrong.

  8. Lee D

    Question - if you're extending your 4G coverage, say, by using these devices, and they themselves connect back over 4G... isn't there a problem here?

    One device fails near the main 4G tower, and the entire street/town all fall over?

    And if you already have 4G reception to the streetlights.... why are you adding more 4G?

    And if you have to do some other backhaul to get to these 4G cells, couldn't you have just done that anyway - because presumably that backhaul ends up somewhere nearby (a BT cabinet or similar) and you could have just mounted a pole or cell on the back of that, no?

    It all seems a bit pointless compared to just slapping into another mobile tower. Maybe relevant in extreme rural areas where you're not allowed to even erect a pole but, then, you were allowed to erect streetlights so presumably a pole of the same height would have the same permissions, no?

    It very much seems a solution in need of multiple problems.

    1. Message From A Self-Destructing Turnip

      I am no expert, but as I understand it the advantage of using numerous smaller cells allows the same frequencies to be reused by different cells at the same time, making more bandwidth available than would be possible with a single large cell covering the same area. The spanner in the works is the backhaul, as linking to a larger cell or daisy chaining through the small cells negates the bandwidth advantage that was created.

      1. P. Lee

        >chaining through the small cells negates the bandwidth advantage that was created.

        Not necessarily. The point is to reduce the collision domain. It's a little like the queue buffers in a switch/router, if data-in temporarily exceeds output capacity, you can store the traffic and send it in an efficient stream, taking advantage of its (hopefully) bursty nature.

        Of course, wires are best, so only use this stuff for devices that need it. That means, stop pushing "wireless internet" for home use. Dig up the roads and lay the fibre! There are good reasons why we don't use wireless networking in data-centres.

  9. EvanPyle


    And here I was drawing up plans for a short 4G tower that I could attach a light to.

  10. Neil 44

    Nothing that new - was news in 2003!


    12:07Tuesday 23 December 2003

    Tuesday, December 23: Lampposts all over Hemel Hempstead may soon not be quite what they seem.

    T-Mobile put in a clutch of planning applications this week for the removal of several lamp standards, to replace them with look-alike telephone masts for the new 3G system for mobile phones.

    The masqueraders are planned to be placed on footpaths outside Greenacres Tavern in Bennetts End, at the junction of Eastbrook Way and Adeyfield Road and on land adjacent to Long Chaulden at the junction with Pulleys Lane.

    1. Simon Rockman

      Re: Nothing that new - was news in 2003!

      The clever thing here is that the lap posts don't have to be removed.

    2. Anonymous Coward
      Anonymous Coward

      Re: Nothing that new - was news in 1994!

      Same approach was used in Metricom's Ricochet wireless system.. 20 years ago! I wonder who's patents expired..). The smaller cells and reduced transmitter receiver distance pay huge dividends in density and bandwidth, and can allow the clients to lower transmit power, lowering the noise floor for other users.

      The decision to keep the back-haul mix and match is GOOD thing, not a tap out. It means the same box can be adapted in a flexible build that uses different back-haul strategies where appropriate, and allows the in place upgrade of components.

      Ricochet used to bounce the signal through a couple of peer nodes till it got back to on with a Hard link. In this case, a directional microwave antenna may serve to get your signal down the block to the nearest street level junction box, then a short hop over to the fiber network.

      Of course in fantasy land, we should put an MIMO AC access point and Micro Cell on each pole, with dedicated fiber links for each node running to a Municipal fiber build.

      I just hope they have good security on those POE ports, otherwise you will have to look for suspicious pass through modules every time you make a call.

      1. Anonymous Coward
        Anonymous Coward

        Re: Nothing that new - was news in 1994!

        I was a Ricochet customer - still have the modem around somewhere. Pretty cool at the time, and the lightposts where I live still have the Ricochet hardware hanging - mostly unplugged from the light sensor. Guess the municipalities never thought about what would happen if they went bust.

        1. IvyKing

          Re: Nothing that new - was news in 1994!

          There are still a few Ricochet repeaters hanging from streetlights around my neck of the woods. Thinking about it, Ricochet was a forerunner to the Light-Squared debacle, as Ricochet's business plan relied on using unlicensed spectrum - albeit LightSquared's spectrum was licensed, it wasn't licensed for what they wanted to use it for.

  11. Sir Runcible Spoon
    Thumb Up

    All hail DA

    and the tome's that just keep giving..

    " SEP (somebody else’s problem)"

    aka how to make mountains invisible :)

    For anyone who hasn't yet read the 6th volume of the trilogy (not by DA obviously) should give it a go. It tries a little hard in the first few pages and overdoes the swearing a bit, but once it settles down is practically indistinguishable (sp?) from DA's prose. So much so I did actually laugh out loud several times whilst reading it - highly recommended

  12. A Ghost

    I represhent zhat remark

    damn, wet trousers again. Where's a lamp post when you need one?


  13. Grahame 2

    Hybrid networking?

    I would have thought a hybrid solution, using fibre to connect main nodes, as fibre can be run parallel to the mains cabling without issue, they could maybe share ducts.

    Then power-line networking over the existing power lines from the main nodes to adjacent lamp post tributary nodes. May need isolation transformers (not sure what the efficiency loss would be) to isolate mains segments to prevent CDMA collisions killing throughput, there also be an issue with the lamp posts acting as RF antenna and leaking interference all over the place.

    Noisy ballasts on the lamps may cause interference, but they could upgrade the lamp to a nice efficient low-noise LED unit while they are installing the cell.

    I am sure there are things I have not thought of, I am not an expert in street lighting.

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