Cell ID and location area codes, please explain

[Anthony5]

My internet connection is with True move 3G and I have problems recently. Surprise surprise..

Speed was fine for the past 4 months, with occasional hick ups, but for the past 10 days or so something has changed.

4G has become available in my area around the same time my problems started, but my aircard can only receive 3G.

Aircard sit outside the house under the carport at a location where I get the best signal.

So the problem now is that my connection may completely freeze for several seconds, so that no websites will load.. A speedtest to Bangkok server may give me 1.5 Mb download and 0.2 Mb upload. The 1.5Mb download is normal, but in better times the upload is also about 2Mb

I have also a True move SIM in my phone, which I have set to UMTS only to not get confused with the LTE signal.and when I perform a speedtest when I experience the problems with the aircard, the results will be similar.

Though on my phone I have also Signal meter installed,and when I run this program while standing at the location of my aircard.

The Cell ID may change several times in a few minutes. Switching between 4 different cells, all while standing at one and the same location.

Normally I have a signal of 73dB, but at those times the signal will be around 85dB.

Not only the Cell id's change but also the location are a code. It will switch between 5505 and 5602. When the cell id's change that mean also my LAC is 5505, when it is 5602 the signal will be stable and get connected to 1 cell only. If that is the case my webuse will also normalize.

So someone can explain what is going on?

[RichCor]

Tower hopping, basically.

Wikipedia gobbldegoop: Location Area Identity

Each location area of a public land mobile network (PLMN) has its own unique identifier which is known as its location area identity (LAI). This internationally unique identifier is used for location updating of mobile subscribers. It is composed of a three decimal digit mobile country code (MCC), a two to three digit mobile network code (MNC) that identifies the GSM PLMN in that country, and a location area code (LAC) which is a 16 bit number thereby allowing 65536 location areas within one GSM PLMN.

The LAI is broadcast regularly through a broadcast control channel (BCCH). A mobile station recognizes the LAI and stores it in the subscriber identity module (SIM). A change of location area gives rise to a location update request.

[Anthony5]

Tower hopping, basically.

Wikipedia gobbldegoop: Location Area Identity

Each location area of a public land mobile network (PLMN) has its own unique identifier which is known as its location area identity (LAI). This internationally unique identifier is used for location updating of mobile subscribers. It is composed of a three decimal digit mobile country code (MCC), a two to three digit mobile network code (MNC) that identifies the GSM PLMN in that country, and a location area code (LAC) which is a 16 bit number thereby allowing 65536 location areas within one GSM PLMN.

The LAI is broadcast regularly through a broadcast control channel (BCCH). A mobile station recognizes the LAI and stores it in the subscriber identity module (SIM). A change of location area gives rise to a location update request.

And why would I be tower hopping if my aircard in fact doesn't move position?

I thought that the Cell ID identified the tower, so probably I'm wrong, but why does it change to 4 different cell id's on the same LAI?

[RichCor]

Covered a bit on Wiki under Mobility Management

see both

Location update procedure

Location area

Possibly your area is covered by several towers, but due to signal fade your system is continually 'hunting' for a better signal.

[Anthony5]

Covered a bit on Wiki under Mobility Management

see both

Location update procedure

Location area

Possibly your area is covered by several towers, but due to signal fade your system is continually 'hunting' for a better signal.

Is there a way to lock an aircard to certain signal?

[RichCor]

Not that I know of.

Some devices allow you to lock certain parameters, but I don't think it works on any of the 'Cell' items (Cell ID Short, Cell ID Long, LAC)

[bamnutsak]

And why would I be tower hopping if my aircard in fact doesn't move position?

Well there is a constant, on-going negotiation based on a number of factors: load, power-saving, (in-)/activity, priorities (voice over data), location (admittedly not a big deal in this scenario), which are all constantly changing.

It will switch between 5505 and 5602.

Can you tell if the MNC changes when the Location Area Code changes? That is, do these have different MNC's (520-04, 520-00, 520-99)?

Maybe use a tower mapping/cell id app. to try and determine more details (locations, providers)?

[Anthony5]

And why would I be tower hopping if my aircard in fact doesn't move position?

Well there is a constant, on-going negotiation based on a number of factors: load, power-saving, (in-)/activity, priorities (voice over data), location (admittedly not a big deal in this scenario), which are all constantly changing.

It will switch between 5505 and 5602.

Can you tell if the MNC changes when the Location Area Code changes? That is, do these have different MNC's (520-04, 520-00, 520-99)?

Maybe use a tower mapping/cell id app. to try and determine more details (locations, providers)?

Yes MCC + MNC changes.

LAC 5005 = MCC + MNC 52000

LAC 5602 = MCC +MNC 52004

On the 5005 LAC I will switch to 4 different cell ID's, while on 5602 LAC I will always be connect to the same cell ID.

[bamnutsak]

Seems like you may be roaming from TrueMove H 3G/2100 (04) to TrueMove H/CAT 3G /850.

You could disable roaming.

[Anthony5]

Seems like you may be roaming from TrueMove H 3G/2100 (04) to TrueMove H/CAT 3G /850.

You could disable roaming.

How do I disable roaming on an aircard Huawei E173?

[RichCor]

You would have to edit your router's modem initialization scripts. Or edit the SIM Card network table.

So not feasible.

[bamnutsak]

Covered a bit on Wiki under Mobility Management

see both

Location update procedure

Location area

Possibly your area is covered by several towers, but due to signal fade your system is continually 'hunting' for a better signal.

Is there a way to lock an aircard to certain signal?

Sorry, should have been more precise.

As I understand your initial post, you have a similar issue with your phone?

I mean, disable roaming on your PHONE, to see if that addresses any issues.

Which network functions better for you? Or is it the brief switch over which is causing problems?

Once we determine which networks works best for you, we can look for alternatives. Obviously, another aircard, which supports either 850 or 2100 (but not both) may be an option?

There may be some firmware options as well which would allow selection on an aircard.

And you could ask TrueMove H to disable roaming.

Is DTAC an option in your area?

[Anthony5]

Covered a bit on Wiki under Mobility Management

see both

Location update procedure

Location area

Possibly your area is covered by several towers, but due to signal fade your system is continually 'hunting' for a better signal.

Is there a way to lock an aircard to certain signal?

Sorry, should have been more precise.

As I understand your initial post, you have a similar issue with your phone?

I mean, disable roaming on your PHONE, to see if that addresses any issues.

Which network functions better for you? Or is it the brief switch over which is causing problems?

Once we determine which networks works best for you, we can look for alternatives. Obviously, another aircard, which supports either 850 or 2100 (but not both) may be an option?

There may be some firmware options as well which would allow selection on an aircard.

And you could ask TrueMove H to disable roaming.

Is DTAC an option in your area?

What happens with the phone is of no concern to me, since at home I don't use my phone to internet, I only use my phone because I can install the test apps on it.

Neither Dtac or AIS are an alternative to me, as I have both tested and found to be worse.

I will look at a 4G aircard, with a 4G router, but I'm afraid it will be the same issue, since they also support both 850 and 2100 Mhz on UMTS.

[IMHO]

Covered a bit on Wiki under Mobility Management

see both

Location update procedure

Location area

Possibly your area is covered by several towers, but due to signal fade your system is continually 'hunting' for a better signal.

Is there a way to lock an aircard to certain signal?

Yes - buy yourself a signal booster, and point the Yagi antenna at your favorite tower - no more hopping and full speed

http://www.hispeedaircard.com/

Curious - did you register the SIM in your 3G dongle?

Edited August 13, 2015 by IMHO

[Anthony5]

Covered a bit on Wiki under Mobility Management

see both

Location update procedure

Location area

Possibly your area is covered by several towers, but due to signal fade your system is continually 'hunting' for a better signal.

Is there a way to lock an aircard to certain signal?

Yes - buy yourself a signal booster, and point the Yagi antenna at your favorite tower - no more hopping and full speed

http://www.hispeedaircard.com/

Curious - did you register the SIM in your 3G dongle?

It's a postpaid SIM.

5500 Bht for a signal booster. Guess I have to think a few days about that.

Edited August 13, 2015 by Anthony5

[Chicog]

If I had to give a quick technical summation, I'd say they bought the cheapest mobile infrastructure crap they could get away with, and that's why it's rubbish.

[Anthony5]

Finally found the problem.

24 port network hub gone bad. Noticed that the router didn't stay connected. First tried to remove one by one the other LAN cables, to see if maybe a corrupt connection somewhere.

Next tried another router I had laying around, and which had the same symptoms.

Then connected a 8 port hub I had laying around, and presto the problem was fixed.

Guess I'll have to talk with the bank tomorrow.

Quick question for those knowledgeable posters.

Is a switch the same as a hub, and is D-link decent quality or should I go with TP-link.

Edited August 16, 2015 by Anthony5

[RichCor]

Don't know of anyone making 'hubs' anymore. Generally everything these days are 'switches' of one form or another.

Hubs are passive, all incoming data go to all outgoing ports.

Switches (or smart switches) can pass all incoming data to all outgoing ports, or just the data destined for the MAC addresses connected on that port. How the Switch operates depends on the hardware design, or if a smart switch then the combination of hardware and firmware presets. But basically everything is a Switch design now.

[Anthony5]

Don't know of anyone making 'hubs' anymore. Generally everything these days are 'switches' of one form or another.

Hubs are passive, all incoming data go to all outgoing ports.

Switches (or smart switches) can pass all incoming data to all outgoing ports, or just the data destined for the MAC addresses connected on that port. How the Switch operates depends on the hardware design, or if a smart switch then the combination of hardware and firmware presets. But basically everything is a Switch design now.

Thanks, so could you maybe explain what the major difference is between these 2 switches. Or in short, will the cheapest one serve my needs?

http://www.invadeit.co.th/product/wired-networking/d-link/24-port-10-100-switch-des-1024a-p020796/

http://www.invadeit.co.th/product/wired-networking/d-link/24-port-fast-ethernet-unmanaged-desktop-rackmount-switch-des-1024d-p015124/

[IMHO]

Don't know of anyone making 'hubs' anymore. Generally everything these days are 'switches' of one form or another.

Hubs are passive, all incoming data go to all outgoing ports.

Switches (or smart switches) can pass all incoming data to all outgoing ports, or just the data destined for the MAC addresses connected on that port. How the Switch operates depends on the hardware design, or if a smart switch then the combination of hardware and firmware presets. But basically everything is a Switch design now.

Thanks, so could you maybe explain what the major difference is between these 2 switches. Or in short, will the cheapest one serve my needs?

http://www.invadeit.co.th/product/wired-networking/d-link/24-port-10-100-switch-des-1024a-p020796/

http://www.invadeit.co.th/product/wired-networking/d-link/24-port-fast-ethernet-unmanaged-desktop-rackmount-switch-des-1024d-p015124/

The cheaper one is designed to sit on a desk, the more expensive one is designed for rack mounting (but can also sit on a desk). Both of them are only 100mbps though, so slower than WiFi.

Do you really need 24 ports of slow 100mbps? If not, you can get less ports, but gigabit speeds for similar money.

I can't see any logical reason why this would impact your 3G speeds, or tower hopping issues you're experiencing. Are you sure this isn't a red herring diagnosis?

Edited August 16, 2015 by IMHO

[Anthony5]

Don't know of anyone making 'hubs' anymore. Generally everything these days are 'switches' of one form or another.

Hubs are passive, all incoming data go to all outgoing ports.

Switches (or smart switches) can pass all incoming data to all outgoing ports, or just the data destined for the MAC addresses connected on that port. How the Switch operates depends on the hardware design, or if a smart switch then the combination of hardware and firmware presets. But basically everything is a Switch design now.

Thanks, so could you maybe explain what the major difference is between these 2 switches. Or in short, will the cheapest one serve my needs?

http://www.invadeit.co.th/product/wired-networking/d-link/24-port-10-100-switch-des-1024a-p020796/

http://www.invadeit.co.th/product/wired-networking/d-link/24-port-fast-ethernet-unmanaged-desktop-rackmount-switch-des-1024d-p015124/

The cheaper one is designed to sit on a desk, the more expensive one is designed for rack mounting (but can also sit on a desk). Both of them are only 100mbps though, so slower than WiFi.

Do you really need 24 ports of slow 100mbps? If not, you can get less ports, but gigabit speeds for similar money.

I can't see any logical reason why this would impact your 3G speeds, or tower hopping issues you're experiencing. Are you sure this isn't a red herring diagnosis?

Indeed they are only 100 mbps, and my internet connection is much much less, so I don't see really any need for one that is 1000 mbps but maybe you can explain why I should.

Yes I need 24 port, because I have 24 contact points in my house,

If you say you can have a 1000 mbps with lesser ports for the same money, I guess you mean 8 ports only, because that is what I could find.

The problem I just discovered is that the hub loses connection with the modem.

If I look at the port light on the hub or the port light on the router, they both disconnect for several seconds at the time.

I switched routers, switched contact point, and also switched ports on router and hub, and it is the same.

When I switch hub the problem is gone.

The strange thing is that with another appliance, like a media player, the problem doesn't exist.

So at this time is the same router, connected to the same contact point, but with another hub doing fine.

Maybe someone can explain that to me.

Edited August 17, 2015 by Anthony5

[RichCor]

Because you have TWO or more 'services' running on your network (Internet Gateway, and a File Server), you should deploy a 'switch'.

While the Internet Gateway port doesn't require a Gigabit port, the File Server could utilize it when servicing media to multiple devices simultaneously, so would be good even if the 'switch' only provided one or two Gigabit Ethernet Ports.

Are you currently running a 24 port hub or a switch? Or maybe a hybrid?

The disconnects are probably caused by MDI-x (auto cross-over detection) being poorly implemented on the 24-port box and constantly resetting.

[Anthony5]

Because you have TWO or more 'services' running on your network (Internet Gateway, and a File Server), you should deploy a 'switch'.

While the Internet Gateway port doesn't require a Gigabit port, the File Server could utilize it when servicing media to multiple devices simultaneously, so would be good even if the 'switch' only provided one or two Gigabit Ethernet Ports.

Are you currently running a 24 port hub or a switch? Or maybe a hybrid?

The disconnects are probably caused by MDI-x (auto cross-over detection) being poorly implemented on the 24-port box and constantly resetting.

What I had was a Zyxel Ethernet switch.

I don't understand what you mean with MDI-x (auto cross-over detection) since I don't have any cross over cables in use, and before last week there was no problem.

Earlier today I tried to ping the routers or other devices connected to the switch.

For that purpose I had connected only 1 or 2 devices at the time, and directly to the switch, and I would always lose 1 or 2 ping packets.

I have today purchased a 16 port D-link switch, and will buy a 8 port gigabit switch, so I have best of both worlds.

However I still don't understand why I would need the Gigabit switch because a Bluray movie peaks at 50 mbps, for which a 100 mbps switch would be more than sufficient.

The D-link 10/100 DES-1016D switch I purchased is labelled that it can run speeds up to 200 mbps at full duplex capability, whatever that would mean.

[RichCor]

MDI-x is a physical wiring scheme detection circuit employed on most Ethernet routers and switches. You may not want it, or use it, but it's there. It's purpose is to detect the RX and TX of an Ethernet Cable, and transpose the pin inputs if it can't sense data being received. When it 'resets' or 'swaps pins' it can cause packet loss (requiring data packet be resent if the protocol in use allows that).

But as you say, the issue is just recent on equipment in place for a long while, so this probably isn't the issue.

GbE ports come in handy when connecting devices that transport lots of data, and lots of data between multiple devices. If your WHS has an GbE card connected to a GbE switch then it can potentially service multiple devices without encountering data collisions and packet loss conditions and packet resends that lead to media playback glitching and pausing.

If you only have one playback device then 100mbps throughput should work fine.

200 mbps full duplex means simultaneous 100mbps send + 100mbps receive.

Older 'hubs' could technically only handle half-duplex communication (Send or Receive, not both simultaneous).

A telephone is full-duplex. You can hear and talk at the same time.

A two-way radio if half-duplex. End 'A' can transmits while end 'B" receives (and waits for end 'A' to shut up. Then end 'B' can transmit while end 'A' receives. They only have one 'pipe' and have to share it's use.

WiFi is half-duplex. Only one WiFi device can send at a time. All the rest must remain silent until it's their turn to transmit.

[Anthony5]

MDI-x is a physical wiring scheme detection circuit employed on most Ethernet routers and switches. You may not want it, or use it, but it's there. It's purpose is to detect the RX and TX of an Ethernet Cable, and transpose the pin inputs if it can't sense data being received. When it 'resets' or 'swaps pins' it can cause packet loss (requiring data packet be resent if the protocol in use allows that).

But as you say, the issue is just recent on equipment in place for a long while, so this probably isn't the issue.

GbE ports come in handy when connecting devices that transport lots of data, and lots of data between multiple devices. If your WHS has an GbE card connected to a GbE switch then it can potentially service multiple devices without encountering data collisions and packet loss conditions and packet resends that lead to media playback glitching and pausing.

If you only have one playback device then 100mbps throughput should work fine.

200 mbps full duplex means simultaneous 100mbps send + 100mbps receive.

Older 'hubs' could technically only handle half-duplex communication (Send or Receive, not both simultaneous).

A telephone is full-duplex. You can hear and talk at the same time.

A two-way radio if half-duplex. End 'A' can transmits while end 'B" receives (and waits for end 'A' to shut up. Then end 'B' can transmit while end 'A' receives. They only have one 'pipe' and have to share it's use.

WiFi is half-duplex. Only one WiFi device can send at a time. All the rest must remain silent until it's their turn to transmit.

I just checked and the server has indeed a Gigabit port, so I will connect the server and all media devices to the Gigabit switch. I may not need it but at 980 + 850 Bht for 8 port Gigabit switch it will not kill the bank.

Is there a way to check if MDI-x is the cause and can it be prevented in some way, because I don't want to add another device I may never use again to my treasury in the attic.

[Anthony5]

Just checked and the Zyxel ES-124P has indeed auto MDI-x support.

Can it be disabled?

[RichCor]

I would probably set up two high-speed devices running Ethernet Throughput Performance Tests connected through the switch to be tested.

Basically you want an app that can toss large amounts of data between computers and measure the response. See if there are data drop-outs.

IPERF is a good app, but it's Command Line -based and a pain to teach someone to use.

[Anthony5]

I would probably set up two high-speed devices running Ethernet Throughput Performance Tests connected through the switch to be tested.

Basically you want an app that can toss large amounts of data between computers and measure the response. See if there are data drop-outs.

IPERF is a good app, but it's Command Line -based and a pain to teach someone to use.

I'm pretty sure that there are data drop outs, because when I do a speedtest to Bangkok server the measure scale acts like a jojo, going from 0.5 to 2.5 and back to 1..2 and up again, all in what is only a few seconds.

When I perform a speedtest right now, with the same aircard and router connected to the the 10 year old hub I had laying around, my download speed is constant and actually more than double of what I have ever tested. So the issue may have always existed but never to the extend it happened recently, and I also have never checked on it because I could live with a download under 2 Mb. It was only after websites didn't load anymore that I started looking at it in detail.

Does this give you any indication, and is there a way to disable this problem or should I toss it in the bin right away?

[RichCor]

Yea, it could have been an ongoing problem.

One of the quickest diagnostics is to swap out a presumed faulty part with something else and see if it works better.

You've done just that and things got immediately better. So there's *something* wrong with the 24 port switch.

Unless there's a 'reset' switch on the thing I'd assume a memory fault has developed (store & forward operation of the switch), and just replace it.

The cost of new switches drop, as you've found, easier to just buy a new one.