Have you ever wondered why your local wireless carrier has placed, on your phone bill, so many roaming charges? In this day and age, customers want to be able to make and receive calls worldwide with little to no effort. There are many things that go into allowing this, at the same time being seamless to the end user while traveling.
Before we get into this article too deep, I feel you should have an understanding of a few basic terms I will be using. There are not many, but these are the cornerstone to how everything works together smoothly.
HLR: Home Location Register. This is a database on your home carriers system that stores everything to know about you and your phone. Some of the things it keeps track of are; Serial Number, Phone Number, and features you have paid for. It also tracks where you currently are which I will explain a little later on in this article.
VLR: Visitors Location Register. This is a database that holds the same information as the HLR but is located on a visiting carrier switch and not your home switch. It also keeps track of where you are but in more details than the HLR.
SS7: Signally System Number 7. This is a protocol that wireless carriers use to talk between each other in order to pass information. It is used for a lot of different messaging, but for this article it is used to talk between HLR’s and VLR’s.
STP: Signaling Transfer Point. These are systems that are used to transport the SS7 Protocol between HLR’s and VLR’s among all wireless carriers.
Now let us start with what happens when you first arrive into a new system by either powering on your phone or by driving. Without you even knowing it, your mobile phone will send a message to the roaming carriers system telling it that they are in the area and would like to be able to use their system. When this happens it, initiates a message from the VLR to its home HLR to gather information on this customer so that when it’s time to make a call it has the data needed to offer the service. It will store this information for a given amount of time determined by the HLR or till the customer drives to another carriers system.
Now, when you go to make a call, the VLR has all the info it needs and process the call based on your feature plan. Nothing fancy happens here. The big issue is when you want to receive a call.
When someone goes to call you, they obviously don’t know exactly where you are and who’s system you are on. If coming from your house, the call is routed by the phone company to your homes system based on your 10 digit phone number. The first thing your home switch does is it looks in the HLR to see if it knows where your phone is currently located. It will have this information, because, when the VLR requested it the HLR logged the info for just this reason. The HLR will see that the customer is being serviced at this time by another carriers system and will forward a message to its VLR stating this customer has a incoming phone call. The VLR will then check its database to verify that they do indeed have the customer on the system as it tracks where exactly the customer is located and will then assign what is called a TLDN. This is basically a temporary phone number that it assigns to the customer for the purpose of receiving the call. The TLDN is forwarded back to the HLR and it in turn forwards the incoming call to this number. That call will then route to the visiting system switch and on to the customer’s phone. Once the call is answered, the TLDN is release by the system so that other customers have it available to receive calls also.
As I was mentioning earlier in this article, HLR’s and VLR’s transfer their SS7 Protocol messaging between each other via nationwide STP’s. These STP’s are systems that third party companies maintain and operate. They operate links to all carriers worldwide. The purpose of these companies are to avoid carriers from having to have links to each company as that can get costly and messy. You hook up to these companies and they have the links in place and just route your messaging for you. There are a couple major companies that offer this service, they are VeriSign and Syniverse. Other companies exist but these are the most popular ones used. These companies also have links to each other for talking to those companies that are with the other. This makes the whole world one big happy messaging link. All carriers have to do after this is sign roaming agreements with a carrier and then notify these STP companies and have them open up the messaging between the associated HLR’s and VLR’s.
In closing: Whether your internationally roaming or just going down the street to your friends. Whenever you leave your home market you could entail roaming changes. Hopefully this article helps explain why those costs are in place. Wireless roaming is a major concern to carriers since latest price plans have started offering it free. Nothing is free in this world, therefore, each call made or received while roaming does ultimately cost the carriers just in messaging costs to STP’s.
There are many things to consider when choosing a wireless provider for all of your personal and professional needs. A wireless phone has become a great part of our daily lives, more than any other technological device to come along in quite a while.
1) Monthly Price Plans
3) Phone Types
4) Roaming Fees
5) Contract Terms
Monthly Price Plan:
Anymore, the monthly price plan has almost completely been turned into a non deciding factor in choosing a wireless provider. You can almost always find that each carrier in your area has the same offers when it comes to the number of free minutes for each varying price plan. The things that vary and you need to pay more attention to are the add-on’s that the carrier uses to make the plans different. These add-ons include things such as voice mail, SMS/texting, and amount of data in MB that you can upload and download without occurring additional charges.
In this determining factor, you have to look at your daily routine. Where is it that you want to be able to send and receive messages or calls? If you are someone that travels frequently, then you need to see which cities you spend a lot of time in and if that carrier is located in that town. Even if they are not your phone will still work but you may incur roaming fees that I will discuss later on in this Hub.
This is more of a personnel decision for you to make. Most people go for physical looks, but you need to make sure it has the functionality that you are after. Look at things such as the keyboard layout, is it comfortable to use, also will it surf the internet if you need it to. Some of the flashy phones are also very fragile. You need to look at your daily routines and make sure that the phone you have chosen can hold up to the beating it will endure while you care carrying it. Also when using the phone to chose your wireless provider, you have to take into account that there are two types of digital phones. One is GSM and one is CDMA, these two technologies will each have different phone models to choose from. The phone you most like may not be available with the carrier you choose due to the digital technology differences.
Many carriers are eliminating these charges and including them in their monthly fees. However, there are still some instances where these can be applied to your situation. Also, there are still some price plans that don’t include free roaming in there offer. These charges are applied when you travel to other locations that your home carrier doesn’t serve. In this situation you are actually using some other carriers system and they in return charge your home carrier a fee for you to use it.
With the exception of pre paid phones, every wireless carrier will have some sort of contract with various terms for you to agree to. If you find yourself wanting to get out of these contracts they can be very costly. The purpose of these contracts, are to allow the carriers to re-coop their costs for the phone that they either gave you for free or at a discounted price when you signed up. This is the reason many chose to use a prepaid phone, however, with those you end up sacrificing other important features you may have wanted.
Wrap Up. There are numerous things to take into consideration when choosing a wireless provider. You need to look at the entire picture of what you need and not just their advertised monthly fee. If you chose the wrong carrier for your needs, you could get caught in a long contract with high fees to cancel, thus forcing you to stay with a carrier even though you are not satisfied with their service.