Devices on same cell tower - curious about data path?

Forums › New Zealand Mobile and Wireless › Devices on same cell tower - curious about data path?

McNulty

152 posts

Master Geek

#228777 22-Jan-2018 13:04

Let's assume a private APN in NZ. Assume smartphone devices using IP-based connections, static IPs, each device is directly configured with one another's static IPs.

I'm curious to know if 2 mobile devices (MobileA and MobileB) connected to the same APN on the same tower (TowerA) will be routed directly to each other? Or will the senders (MobileA) traffic need to traverse to some sort of Central Office before returning along the same path to the receiver (MobileB)?

What about if there is a server (ServerA) in a branch office "near" the very same tower (assume same CO), same Telco/ISP as TowerA but using UFB side of the business. What is the datapath in this case for MobileA to ServerA? Local or could it potentially go halfway up the country and back?

Bonus questions:

Would this be any different for Voice?

Different for different Telcos?

tdgeek

29751 posts

Uber Geek

Trusted

Lifetime subscriber

#1944743 22-Jan-2018 13:23

I'd have thought it will act the same as if one device was in Cape Reinga and the other was in Stewart Island

Down the tower, through the fibre to the Telco hub, through the fibre back to the tower, up the tower, and holler to the other device

Linux

11432 posts

Uber Geek

Trusted

Lifetime subscriber

#1944772 22-Jan-2018 13:54

GGSN handles private APN data traffic so no way traffic will be direct to each device, GGSN sits back in the core mobile network

Linux

McNulty

152 posts

Master Geek

#1944777 22-Jan-2018 14:10

Linux: GGSN handles private APN data traffic so no way traffic will be direct to each device, GGSN sits back in the core mobile network

Linux

Aha. So would it be different for the main public APN then?

McNulty

152 posts

Master Geek

#1944781 22-Jan-2018 14:19

tdgeek:

I'd have thought it will act the same as if one device was in Cape Reinga and the other was in Stewart Island

Down the tower, through the fibre to the Telco hub, through the fibre back to the tower, up the tower, and holler to the other device

Depends what Telco Hub means in reality? There are cabinets full of equipment at the base of the towers...they could probably run some "Hub" functions from there.

tdgeek

29751 posts

Uber Geek

Trusted

Lifetime subscriber

#1944784 22-Jan-2018 14:26

McNulty:

tdgeek:

I'd have thought it will act the same as if one device was in Cape Reinga and the other was in Stewart Island

Down the tower, through the fibre to the Telco hub, through the fibre back to the tower, up the tower, and holler to the other device

Depends what Telco Hub means in reality? There are cabinets full of equipment at the base of the towers...they could probably run some "Hub" functions from there.

Generic name for core mobile network

Linux

11432 posts

Uber Geek

Trusted

Lifetime subscriber

#1944785 22-Jan-2018 14:26

McNulty:

Linux: GGSN handles private APN data traffic so no way traffic will be direct to each device, GGSN sits back in the core mobile network

Linux

Aha. So would it be different for the main public APN then?

All APN's are on the GGSN private / public

Linux

McNulty

152 posts

Master Geek

#1944788 22-Jan-2018 14:34

Linux:

McNulty:

Linux: GGSN handles private APN data traffic so no way traffic will be direct to each device, GGSN sits back in the core mobile network

Linux

Aha. So would it be different for the main public APN then?

All APN's are on the GGSN private / public

Linux

I thought that GGSN is only to get from mobile network to Internet. Didn't realise that every packet has to pass here. Was hoping to hear about some awesome new SDN technology in play.

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

Linux

11432 posts

Uber Geek

Trusted

Lifetime subscriber

#1944790 22-Jan-2018 14:37

What actually are you trying to achieve or find out? How the core routes packet data or circuit switch should not matter to the end user

Linux

McNulty

152 posts

Master Geek

#1944801 22-Jan-2018 15:00

Linux:

What actually are you trying to achieve or find out? How the core routes packet data or circuit switch should not matter to the end user

Linux

I want to have lowest possible latency between MobileA and MobileB, and between MobileA/B and ServerA using cellular technology.

It is a theoretical exercise because I'm curious.

yitz

2081 posts

Uber Geek

#1944808 22-Jan-2018 15:09

For mobile to server the closest you'd get is if you had your application hosted by the telco. Geographically you'd have to confirm your chosen solution with the telco, I'd expect the round trip in either case to be least via the closest main centre.

tripper1000

1617 posts

Uber Geek

#1945518 23-Jan-2018 15:19

I know very little about the specific's of cellular network architecture, however in most wireless networks, the part that contributes the most to latency is the air link and associated modulation and demodulation. That is why gamers, and others who are particular about latency, avoid and eliminate wireless connections as much as possible. I'd expect that even if it was possible, manipulating the routing within the Telco network isn't going to improve latency much.