Do you think mobile phones will ever get proper peer to peer communication? - Page 1
Forum section: electronics / general

author: e100
author_rank: Frequent Contributor
timestamp: March 24, 2024, 08:08:24 am
content: As in bypassing the telcos for short distance communication, for example for text and voice communication within an office complex.The technology certainly exists as proven by mesh networks such as Meshtastic etc. and modern phones are already packed with transceivers covering multiple frequencies and protocols.The big players such as Apple and Samsung don't seem to be wedded to any particular telco so there is no great motivation to be locked into the telco model, which incidentally is just a complete mess with extreme regional fragmentation and lack of cooperation between providers.

author: coppercone2
author_rank: Super Contributor
timestamp: March 24, 2024, 09:07:58 am
content: they use teams for that

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 24, 2024, 09:21:49 am
content: Short answer: probably never because they have absolutely nothing to gain from that, and if "offline" communication ever became mainstream, governments would ban it in an instant.

author: janoc
author_rank: Super Contributor
timestamp: March 24, 2024, 12:13:39 pm
content: Quote from: e100 on March 24, 2024, 08:08:24 amYou could do that but it makes little business sense - unless there is some open standard everyone uses (there isn't) or everyone has the same device/phone from the same vendor (not realistic) it wouldn't work. There is also very little commercial incentive in developing something like this because there are already better solutions available for addressing this problem.Also that you can connect to a phone BTS a kilometer or two away with your phone doesn't mean that the same transciever will be capable of "hearing" another such radio two rooms away behind several walls. The BTS has huge (compared to the phone) antennas so it can hear the puny signal from the phone far away and has a fairly powerful transmitter as well. Phones trying to talk directly to each other at these frequencies used by the GSM/LTS/Wifi/Bluetooth networks would work well probably only in an open space, not in buildings full of concrete walls, rebar and interference. Never had situations where you had poor reception unless you were right next to the window? Now imagine you aren't talking to a BTS with 100W of power and a large antenna array on top of a building or a hill but a 2W (max) phone somewhere in the basement. Ain't gonna happen.Quote from: SiliconWizard on March 24, 2024, 09:21:49 amThat is not quite true. Back in the late 90s/early 2000s there were phones that had a "walkie-talkie" function (PTT - "Push to talk"), for this purpose. It is not strictly speaking "peer to peer" (radio talking directly to each other - it used GPRS over the GSM network and you still needed to have the service supported by the network) but from the user's point of view there was little difference.So this kind of feature has been tried already. E.g. Nokia 6101 series had this function. It didn't quite take off in Europe, though, because there is zero advantage in it for consumers over just making a regular call/sending a text. And if you really need a walkie talkie instead of a phone (e.g. when staffing events or to communicate inside of a warehouse, hiking, camping, etc.), then these are cheaply and widely available.Modern smartphones also have plenty of apps available for such peer-to-peer messaging over IP (e.g. corporate wifi) or even directly over Bluetooth. However, for companies this makes little sense because it would be a security and compliance nightmare trying to secure the vast array of personal devices brought in by the staff.Concerning the conspiracy about governments banning something in an instant - come on. Spare that tinfoil hat. As if you couldn't buy a cheap walkie-talkie radio in almost every supermarket or sports store, no license, registration or subscription required, as "offline" as it gets.And if you want/need something more powerful, with more range then there are options as well, such as:https://myrealmobile.com/push-to-talk-ptt-over-cellular-rm-1560-dual-4g-lteanalog-radio. That is a 70cm radio + 4G LTE phone in one, if you really need this capability. Or one of many trunking radio systems (e.g. TETRA) widely used by taxi services, fire and rescue, etc.Most people don't need this, that's why it isn't widely sold, not because some government cabal has banned/would ban it.

author: soldar
author_rank: Super Contributor
timestamp: March 24, 2024, 08:25:52 pm
content: Quote from: janoc on March 24, 2024, 12:13:39 pmInteresting. I did not know such a thing existed. As you say, the need for something like that is extremely limited. In most cases you are better off having separate phone and walkie.I suppose if tower traffic gets too congested there might be an advantage but in reality what is happening is that with 5G cellular cells are getting smaller. Being on the cell network you can move or stay close. yeah, I do not see the advantage of peer to peer phones.

author: coppice
author_rank: Super Contributor
timestamp: March 24, 2024, 10:05:40 pm
content: Quote from: e100 on March 24, 2024, 08:08:24 amWe already have communications within an office complex implemented on our phones. Its called wi-fi. There are plenty of ways for phones to talk to each other over wi-fi. A lot of telcos will route your cellular calls over wi-fi when a cellular connection is not available. That mitigates poor cellular coverage deep in buildings. If you want independence from the cellular operator, there are number VoIP and other options for calls within a local area over wi-fi.

author: nctnico
author_rank: Super Contributor
timestamp: March 24, 2024, 10:10:46 pm
content: Quote from: e100 on March 24, 2024, 08:08:24 amAlready exists. Connect your phone to the building's wifi and call through Whatsapp or something similar.

author: jonpaul
author_rank: Super Contributor
timestamp: March 24, 2024, 11:02:10 pm
content: no. GSM, CDMA, and other telecom stds require handshake to a cellular tower.All comms mobile to mobile are routed Mobile 1 >>cell tower 1 >>network, cloud>>Cell tower 2>>mobile 2.Beside BT and Wifi there is no connection mobile to mobile.j

author: ejeffrey
author_rank: Super Contributor
timestamp: March 24, 2024, 11:41:39 pm
content: Quote from: e100 on March 24, 2024, 08:08:24 amIt's nothing compared to the fragmentation and lack of cooperation between mobile phone manufacturers and communications app vendors. Whatsapp can't talk to facetime can't talk to zoom can't talk to MS teams cant talk to Google meet can't talk to Google hangouts can't talk to Google chat can't talk to Google voice...

author: pdenisowski
author_rank: Super Contributor
timestamp: March 25, 2024, 12:42:54 am
content: Quote from: janoc on March 24, 2024, 12:13:39 pmIn the United States, iDEN was very popular for a while but Sprint refarmed the spectrum to LTE sometime around 2012 (?) or so.

author: pdenisowski
author_rank: Super Contributor
timestamp: March 25, 2024, 12:48:37 am
content: There are 3GPP standards for direct UE-to-UE communications ("sidelink")https://www.comsoc.org/publications/ctn/who-needs-basestations-when-we-have-sidelinksI'll have to check with my colleagues who specialize in mobile wireless to see if anyone is actually implementing this.

author: David Hess
author_rank: Super Contributor
timestamp: March 25, 2024, 02:44:25 am
content: PDAs used to support IrDA for local point-to-point connections. Business persons could trade business cards using this. Or you could synchronize your PDA with your computer just by setting it down in front of it.

author: dobsonr741
author_rank: Frequent Contributor
timestamp: March 25, 2024, 04:00:12 am
content: Voice calls are no longer cool. Or driving telco revenue. What remains is messaging over WiFi, and that is telco-less.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 25, 2024, 04:13:29 am
content: They exist, but haven't caught on. The carriers not liking alternatives to their services is likely part of why.

author: e100
author_rank: Frequent Contributor
timestamp: March 25, 2024, 04:35:36 am
content: Quote from: ejeffrey on March 24, 2024, 11:41:39 pmThe telco SIM system is way worse because it is is region locked. If you step off a plane in another first world country without planning weeks ahead and purchasing a regional SIM or roaming plan, you will literally have no service, not even text. On my last trip I had to carry two physical phones and switch from one to the other when the plane landed. That is completely insane.

author: pdenisowski
author_rank: Super Contributor
timestamp: March 25, 2024, 09:10:43 am
content: Quote from: e100 on March 25, 2024, 04:35:36 amI have an iPhone and "normal" service with one of the major United States network operators: I can travel to any major country in Europe and Asia and my phone works without having to change SIMs, notify the carrier in advance, etc. Yes, I have to pay a (frankly, pretty reasonable) per-day charge, but I've never not had service in a "first world" country.Maybe a business issue rather than a technical issue?

author: David Hess
author_rank: Super Contributor
timestamp: March 25, 2024, 12:30:01 pm
content: Phones can link into Meshtastic using Bluetooth and Meshtastic can provide secure local communications. Now we just need a phone which support LoRa directly.https://meshtastic.org/docs/introduction/

author: tom66
author_rank: Super Contributor
timestamp: March 25, 2024, 01:00:54 pm
content: I don't think it's practical for the way phones are used these days, because you need long distance calling and routing a call through possibly hundreds of other phones will always be less reliable and have greater latency than going through cell towers.

author: Berni
author_rank: Super Contributor
timestamp: March 25, 2024, 01:20:41 pm
content: Quote from: e100 on March 25, 2024, 04:35:36 amNo problem just buy a satellite phone and buy a SIM card for the Inmarsat network. The monthly plans are not exactly cheep but you can use it to make phone calls and enjoy a 64kbit/s internet connection in every country in the world. Heck it even works in international waters in the middle of the pacific ocean.So far every country i visited in Europe my regular home cell provider SIM card worked fine. The only problem was that places outside the EU are not covered under the EU telecommunication laws, and so they make their roaming services insanely expensive (like literally 100x the price). So if you plan to make significant use of the cell network there it is a good idea to buy a local SIM card, but you are not forced to do it, you can still just eat the expensive fees and use your existing home SIM.How would you expect a P2P phone system to solve any of this? Do you expect your phone call to hop from phone to phone across an entire continent or something?

author: tom66
author_rank: Super Contributor
timestamp: March 25, 2024, 01:35:17 pm
content: Or just buy an international eSim before you go, sometimes you can even buy this at the airport (though expect to pay a premium). It is a QR code you scan which gives you x days of service, usually data only, but if you want you can add a phone number and get texts/calls too.

author: coppice
author_rank: Super Contributor
timestamp: March 25, 2024, 02:00:16 pm
content: Phones are designed on the basis of one small lousy antenna interacting with a large high performance one. If you are interested in peer to peer phone communication you need one of the trunk radio protocols, which still use a base station for negotiation, but send the signal peer to peer once communication is established. Something like TETRA. Those are not the most compact things you will ever use.

author: Kosmic
author_rank: Super Contributor
timestamp: March 25, 2024, 02:50:37 pm
content: Quote from: coppice on March 25, 2024, 02:00:16 pmI echo coppice's comment. The cell phone is a bad transmitter and receiver (because of size and power consumption) and the cellphone tower is a really good transmitter and receiver. So the tower compensate for the cell phone and is an important part in the design of the whole system.If you want short distance communication between devices, better to use Bluetooth.I use to work for a company that was making self-forming and self-healing mesh network and the limitation on latency and bandwidth was significative. They ended up finding a good fit in underground mines where traditional structured wireless technologies (cellular, wifi) are not really viable.In general, peer to peer technologies are really inefficient.

author: Kosmic
author_rank: Super Contributor
timestamp: March 25, 2024, 03:18:19 pm
content: Quote from: pdenisowski on March 25, 2024, 09:10:43 amThe standards has been merged since 4G I believe. So, if your phone is not vendor locked, it should work everywhere. Doesn't mean it's going to be cheap though since your provider will charge you for using your device outside your normal zone.The only technical issue left is frequencies used, since those are regulated per region. Your device might not support them all.

author: David Hess
author_rank: Super Contributor
timestamp: March 25, 2024, 08:09:55 pm
content: Quote from: tom66 on March 25, 2024, 01:00:54 pmThe question was about peer-to-peer communications. Meshtastic would allow a slightly wider context, but does not scale up.As in bypassing the telcos for short distance communication, for example for text and voice communication within an office complex.