“ Hi , I ’d like a large barbecue poulet pizza with extra—*fzzt * oni * asjkhwakj * no * kssshh * ” CALL FAILED . What just happened here ? With all of today ’s forward-looking wireless technology , why do cellphones still commit this shit ?
For all the heaven-sent things we ’re capable to do with phones now — severalise 600 Twitter followers unpleasantly intimate details of our liveliness , for instance — it ’s amazing what ’s still pretermit : Universally splendid reception . Without enough bar , your sound becomes a shining , useless brick . We ’ve already explain howcell pillar fundamentally work . Now , we ’re gon na peach about how the inconspicuous fairies who carry your spokesperson and datum between the prison cell site and your Moto RAZR really do their job .
https://gizmodo.com/giz-explains-how-cell-towers-work-5177322
Okay , there are no fairy . Everything is actually carry onradio wave — ultra high oftenness ( UHF , as in the Weird Al movie)radio Wave , to be precise . UHF refers to any frequencies between 300MHz and 3GHz , so Wi - Fi , your mom ’s cordless phone , your halting Bluetooth headset and other clobber all fly the coop on the panoptic UHF ring . The thing about radio receiver waves is thatthey’re jolly easy to screw with , and UHF is no exception , despite the fact it has “ ultra ” in the name . peradventure if we had like , Chuck Norris Frequency , things would be different .
The hitch
You ’re walking around with a canonized walkie talkie . It ’s give off wireless waves , and trying to catch others that get along from a tugboat . So a vast reason that you sometimes get a sign frail than bodega coffee is stuff getting in the direction . And the far away from the cell tower your are , the more likely it is that stuff and nonsense is gon na get in your way , even if the radio moving ridge are hard enough to reach you .
Since the frequencies for cell serviceessentially travel in a straight bank line , you ’re screwed if you tramp behind a big hill or construction . Big obstruction are manifestly fuss , but small obstacles make huge problems too . unlike materials have different effects on the radio waves , since they are subject to thing like reflection and absorption . A building with mess of reflective alloy on the outside is gon na have a crummy signal in spite of appearance . Conductive materials have a tendency to ingest and weaken , ( or “ rarefy ” ) the sign . ( This is why you ca n’t forge a phone entirely out of aluminum . ) Plants , while friendly to the earth , arenot friendly to cell signalssince they absorb the signal .
The Frequency
It also depends on what oftenness you ’re hustle on . Today , Verizon and AT&T use 850 and 1900MHz . T - Mobile utilize the 1700 , 1900 and 2100MHz banding , mostly 1900 . Nextel ’s iDEN web uses 900MHz , while Sprint ’s main web runs on 1900MHz with roaming on 800MHz . The Sprint / Clearwire WiMax meshwork is higher up , at 2500MHz , aka 2.5Ghz .
The reason the 700MHz is such red-hot property for AT&T and Verizon ’s upcoming high - f number 4 G LTE deployment is thatlower - frequency signals move around fartherand allegedly get through some materials better using the same might as a signal on a mellow frequency . This is why LTE is suitable for rural broadband deployment .
https://gizmodo.com/verizon-promises-more-coverage-with-4g-than-it-now-prov-5194952
( Significantly gamy frequencies in reality do penetrate certain thing better at tightlipped range and with more power , so this whole discussion can quick ferment into a vexation factory if you rent it . )
AT&T is presently shifting a lot of their 3 chiliad to 850MHz for dear penetration after everyone with an iPhone cried about their stinking reception . So being on a lower absolute frequency potentially poses a good chance to have a more solid sign .
uncalled-for to say , the more noisy a particular frequence , the more trouble calls can encounter as well , so carriers have to manage their bandwidth like freeway designers , to avoid the congestion that also contributes to throw telephone call .
The Handoff
handoff ( aka handovers ) are another reasonableness your order for a pizza with additional tall mallow might move around into one for extra soil , specially if you ’re flying down the main road at 60 mph and your earpiece is wirelessly take a hop from cubicle tower to cell towboat . All sort of wonky things , like ping - ponging between the two towers , can take place that ’ll lead in a dropped call , specially if it ’s between two stations that are n’t in line of sight .
The Backhaul
Okay , you say , but I have full bars goddammit . Explain that . Well , for one , full barsdoesn’t necessarily mean anything . There ’s no industriousness yardstick that translates the bars into actual information , but they all basically make up norm of signaling strength over small lump of time . But just because the signaling strength is good , that does n’t entail the call ’s going through .
For fledgeling , there are only a finite number of calls a cell column can do by , which varies depending on the demands of the phone or wireless modem . As calls get in , they are juggle by the tug , then routed through a wired connection ( or on occasion a powerful wireless connection ) to the greater telecom infrastructure . This is call backhaul , and it can be a bottleneck .
Assuming you ’re all dear , with a fantastic sign and a whorl on the tower , but still , your Yelp reviews are n’t flowing like they should . Do n’t forget , at some point , like any dial - up or cable modem , your cell data postulation have to vie with everything else on the internet . Even shout are so digitalized these day , their “ packet ” of datum can be disturb by nameless internetty forces .
The last object lesson there ? The fatter the hard pipe , the more datum it can address — roughage is the best , patently , but most tower still use an array of T1 line . And that bottleneck , asOm pointed out last class , could be fluid broadband ’s liberal barrier . Assuming you get past all those other roadblocks .
https://gizmodo.com/giz-explains-what-you-didnt-know-about-the-iphones-3g-5015307
Still something you still wanna know ? Send any questions about cellular telephone , hotlines , or Jason Chen ’s pants to[email protect ] , with “ Giz Explains ” in the subject line .
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