Use 5Ghz Wifi for an communication between devices?! - Page 1
Forum section: electronics / rf-microwave

author: Lord of nothing
author_rank: Super Contributor
timestamp: November 19, 2018, 11:44:30 pm
content: HiSimple problem. I need a Data connection between 2 or more device outdoor.Now the problem start.LTE -> not available everywherePMR446 -> no way to connect the Radio to the PDA + just 0,5WCB -> 10W SSB legal but to bulky to carry around433Mhz, 868Mhz -> 10% Duty Circle, very low output power"private LTE" -> no Wideband Channel Available for and maybe to expensive if the would have space forSo what elese?I think about 5Ghz LTE who is permit to use 1W Outdoor.So is there some Module who allow me to build a Mesh Network?THX!

author: cdev
author_rank: Super Contributor
timestamp: November 23, 2018, 12:44:36 am
content: A number of companies are selling very fast 60 GHz devices that work line of sight. Don't know the cost offhand but I am pretty sure its quite reasonable considering the speed.

author: Lord of nothing
author_rank: Super Contributor
timestamp: November 23, 2018, 01:53:25 am
content: speed is not the problem its more the range.

author: David Hess
author_rank: Super Contributor
timestamp: November 23, 2018, 04:00:20 am
content: If you just want stuff to plug together, then I suggest some Ubiquity 5GHz WiFi APs.

author: Gribo
author_rank: Frequent Contributor
timestamp: November 23, 2018, 05:41:50 pm
content: What is the required data rate? What level of reliability?

author: Marco
author_rank: Super Contributor
timestamp: November 23, 2018, 06:15:03 pm
content: How about a bunch of Pi3s with OpenWRT and mesh networking?

author: tautech
author_rank: Super Contributor
timestamp: November 23, 2018, 06:42:01 pm
content: Quote from: David Hess on November 23, 2018, 04:00:20 am+1Our ISP uses their stuff exclusively.Look at their air fiber and air max products:https://www.ubnt.com/products/#defaultCurrently we're on a 5 GHz 10 km link and about to upgrade our modem as we're at the limit of its 100MB/s LAN ports.Looks like I'll be providing an additional 'high site' soon for an 11 GHz link to relay to villages further to the west of us.

author: OwO
author_rank: Super Contributor
timestamp: November 25, 2018, 02:38:57 pm
content: If you don't have (near) line of sight then anything beyond 1GHz won't really work well; I have done plenty of propagation tests on 900MHz, 2.4GHz, and 5 GHz. 2.4GHz gets attenuated 10 to 20 dB by just a layer of trees, and 5GHz is even worse. If there are buildings in the way forget 2.4/5GHz. With sufficient link budget 800/900MHz will get past one or two layers of buildings, but you will lose at least 20dB.Near line of sight & low data rate (<100kbps): easy to achieve on all bands; just choose a decent single chip transceiver like the TI ones or the AX5043 (pay attention to the datasheet; the NRF ones aren't very sensitive).Near line of sight & high data rate: just use off-the-shelf wifi equipment (like ubiquiti as mentioned.)Non line of sight & low data rate: use 863/915MHz, AX5043, and power amplifier for full legal power. Pay attention to the design of the receiver; use a SAW filter and LNA, but use only just enough LNA gain (too much gain fucks up overall receiver linearity).Non line of sight & high data rate: impossible without repeaters.

author: Lord of nothing
author_rank: Super Contributor
timestamp: November 27, 2018, 02:22:47 pm
content: sry for the late replay.QuoteI need some Handheld device.QuoteMust work with VoIP and Data. I will transfer some Data for example for the Checkin and other. The Bandwith is not that problem when I use a "Wide Band" connection.QuoteSize and I would need to 3D print some Case to get them Watertide.QuoteThere are just 868Mhz Band but the are very limited with a 10% Duty Circle and so one.Code:1Radiocommunication ServiceMobile Service2ApplicationWideband Data Transmission SystemsThis set of usage conditions is only available for wideband SRDs in data networks.3Frequency band863 - 868 MHz4Channelling5Modulation / Occupied bandwidthBandwidth: ≤ 1 MHz.6Direction / Separation7Transmit power / Power density25 mW erp8Channel access and occupation rulesTechniques to access spectrum and mitigate interference that provide at least equivalent performance to the techniques described in harmonised standards adopted under Directive 2014/53/EU must be used.Duty cycle: ≤ 10 % for network access pointsDuty cycle: ≤ 2,8 % otherwise.

author: Marco
author_rank: Super Contributor
timestamp: November 27, 2018, 02:47:51 pm
content: Quote from: Lord of nothing on November 27, 2018, 02:22:47 pmMost hardware does not come waterproof. As for size, how aboutthisorthis? Or alternatively just some more compact SBC with an USB 5GHz adapter and Libremesh/OpenWRT.

author: Lord of nothing
author_rank: Super Contributor
timestamp: November 27, 2018, 02:50:25 pm
content: A Mash Network would be the best. All 868Mhz, 433Mhz is rubbish.

author: Marco
author_rank: Super Contributor
timestamp: November 27, 2018, 03:04:31 pm
content: For very low dataratethislooks interesting.

author: Lord of nothing
author_rank: Super Contributor
timestamp: November 27, 2018, 03:19:32 pm
content: Hmm it depend. If you want use for a Light Switch, Temerature Control/ Measurement, ... Yes.For anything else? No. The problem is with the legal stuff.The problem is the 10% Dutycirclye and very low output power with 500mw, 100mw or even 10mw.Thats ok when you use some "repeater" at Home.

author: Marco
author_rank: Super Contributor
timestamp: November 27, 2018, 05:22:25 pm
content: Power alone doesn't determine the link budget. 10x the power over 1000x the bandwidth isn't going to do you any favours if you don't need that bandwidth.As for duty cycle, depending on the throughput and latency you need it doesn't need to be a problem. So better to specify those than continuing to complain about it

author: Lord of nothing
author_rank: Super Contributor
timestamp: November 27, 2018, 05:48:52 pm
content: When my 2W (or what the real output power) of the China Radio on UHF had problem to receive a Signal how does a 100mw on 443Mhz perform or on 868mhz?Sure with a 10W CB Radio I can write with People from France or Spain its true but with perfect condition.

author: Marco
author_rank: Super Contributor
timestamp: November 27, 2018, 05:57:36 pm
content: Look at a cheap narrow band modem like say the AX5043, the sensitivity differs almost 30dBm between 0.1kbps mode and 125kbps mode, that's a factor 1000 in power. That's how.So what throughput and what latency do you require?

author: Lord of nothing
author_rank: Super Contributor
timestamp: November 27, 2018, 06:06:14 pm
content: The problem is I cant use a Chipset. The must be a "certified" Product who declare to be confirm with the Regulation.(Like every product who transmit t.)QuoteI dont have any Checkin System right now so I cant say.Latency will not be that problem. Its important to transmit the Data who board wich Bus for example and Manage the Baggage Tags without an Cellular Network.(Sure I will be use it if there is a Signal but I need a Backup System if not).The "main Problem" is the must be licences in the whole EU. I life in Vienna who is near CZ, SK, HU, SI who we want make Trips to.So a "traditional" Commercial Radio System would not work becouse we must turn the Radio near the Boarder or pay Licence fees for every Country. That would cost more than Roaming.

author: tautech
author_rank: Super Contributor
timestamp: November 27, 2018, 06:42:26 pm
content: Nowhere have you mentioned the range you need.Knowing that will assist with selection of a satisfactory device.

author: Lord of nothing
author_rank: Super Contributor
timestamp: November 27, 2018, 06:53:32 pm
content: When I tell you from the Top Platform from your Main Station in Vienna and the Main Hall I gues nobody will have an idea how many Doors, Platforms, Stairs,... are between.

author: tszaboo
author_rank: Super Contributor
timestamp: November 29, 2018, 09:15:56 am
content: Quote from: Lord of nothing on November 27, 2018, 06:06:14 pmThat is not how it works. CE+CE != CE. Also, if you place a radio modem in anything, you need to certify it to IEC 61000 or RED amongst others. Even if you use a module.And roaming doesnt exist anymore.And we still dont know, if you need 100 Mbit/s of speed or two message per day.