Evolution
of cellular systems
The second category of
technologies used in mobile communications is reserved for cellular systems,
both analog and digital. These systems are aimed at mobile communication
from anywhere you are (always within a coverage range that covers cities and
large areas between towns), even when you are on the move.
This category, from its
beginnings with the first generation at the beginning of the 80's, has
undergone great evolutions until reaching our days with the fourth generation
(and the imminent fifth generation that is to come).
Initially ,
first-generation analog mobile telephony was nationwide. This
meant that each country regulated and developed its own mobile phone systems,
most of the cases not being compatible with the terminals of one country with
those of another. Basically they consisted of transmitting telephone calls
by radio, so with a radio station, an antenna in conditions and selecting the
correct frequencies you could listen to conversations of this type of
telephony. It was also oriented to voice transmission, not being possible
to transmit data.
With the second
generation in the mid-90s came the GSM (Global System for Mobile
communication), which came to standardize this type of telephony at European
level and also to convert it into digital, with which the
transmission of data was already possible, and also the same terminal could be
used in the different countries that adopted this system (this type of use came
to be called 'roaming'). This system also encrypts communications, with
which, in theory, it is no longer possible to listen to the conversations that
are established, although later it was shown that the encryption algorithm used
(the A5 / 1) was weak (it based its robustness on secrecy algorithm, which
could be discovered through leaks and reverse engineering) and could be broken,
thus causing security holes. Within this generation, certain improvements
were made, which mainly made it possible to send data at a higher
speed. The most prominent ones were GPRS at first, increasing the data
transfer rate by more than 10 times and EDGE a little later,
The 3rd
generation began to be implemented in 2004 and was already specially
designed to be able to support all types of multimedia communications
with audio and video.. At the beginning with the UMTS standard in
which we could already talk about Mbps in data transfer rates. Later with
HSPA and HSPA + the transfer rate was increased even more. In this
generation, the encryption system was improved using the KASUMI stream
encryption algorithm, also called A5 / 3 although later this algorithm has also
had cryptanalysis studies and although it could be r0mper through a related key
attack, this attack did not It is applicable to the way A5 / 3 is used in 3G
systems, however, this is a discrediting of the algorithm that raises more than
reasonable doubts about its security.
More or less in 2008 4G
technology began to take shape , although it was not until
mid-2013 that this technology did not reach Spain. 4G is characterized by
the LTE system and especially LTE-A that already provides IP
communicationpoint to point with a good quality of service (QoS). LTE
does not have native voice traffic, instead it uses Voice over IP (VoIP) which
has better integration with all multimedia services. LTE-A is capable of
reaching theoretical download speeds of 1 Gbit / s. As for LTE security,
you can use the IPSec protocol in tunnel mode with ESP and also authentication
with IKEv2. Basically they are the tools used in the establishment of
tunnels through VPN and that offer a very robust security thanks to the
mechanisms of confidentiality, integrity and availability. The problem is
that the 3GPP standard that regulates this standard leaves the condition of
using these security tools as optional, therefore, not all operators comply
with it. There is also a new radio element (the eNodeB) that is
susceptible to being attacked locally or remotely. If an attacker were to
gain physical access to the eNB, he could intercept, modify, or inject traffic
into the network. This can cause major security flaws.
ESIM
card
With the evolution of digital
mobile telephony, the SIM card, which was related to the data and the
subscriber number, has also evolved. At first the SIM card was similar in
size to a credit card, although the chip with the information was only a small
portion of all the plastic. So it was soon reduced in size to the 2FF form
factor also called 'MiniSIM', which was present in all terminals until a few
years ago, due to the advancement of technologies and wanting to increase the
space inside the terminals. adopting new form factors: the 3FF also called
'MicroSIM' and the 4FF also called 'NanoSIM'.
The decrease in the
size of the SIM seems to have already reached its minimum
level. It is difficult to reduce the size again without having to reduce
the contacts of the card and / or the chip inside. So there has been a new
revolution and it has been decided to eliminate this tool by introducing it
into the circuitry of the terminals.
For any device
Thus, all those terminals that
are intended to connect to the mobile network (they do not have to be
smartphones, this new SIM format opens the door to any device that wants to
connect to the mobile network, such as smartwatch, tablets, laptops and
in the near future, any household appliance that wants to be
integrated into the Internet of Things (IoT, no matter how small), will
have an integrated chip designed to store the information that was
previously stored on the SIM card.
Goodbye SIM, Hello eSIM card
Until now, when we wanted to
call or connect through the mobile network, we needed 2 things: A terminal to
connect and a SIM card provided by the mobile service operator that we had
contracted. However, with the new eSIM card what
we will have is a terminal to which the new chip will have to
be " programmed" with the subscriber's data.provided by
the mobile phone provider (by e-mail, telephone, mail, web, etc ...). This
programming will be done with a software that will already include the terminal
itself and with the data that the provider will provide us, for example, on
smartphones it will be done by scanning a QR code that the provider sends you,
although it will not be done in all terminals Thus, since for example
smartwatches that do not have a camera, the information will have to be entered
manually.
This gives us a series of advantages ,
such as not having to go to an operator's point of sale to get a SIM card with
which to call, or having to wait for the courier to deliver the SIM card, which
most Sometimes it was difficult to match and delivery could be delayed longer
than desired. Another important advantage is that unlike the physical SIM,
several subscriber numbers can be stored in the eSIM, that is, we can have, for
example, on the same Smartphone, the personal phone number and the work phone
number, although only one of the plans may be activated, eliminating the
possibility of working with dual SIM like some current
terminals that have a double tray to store 2 SIMs and work together with both
(although only one of them connected to the data plan but both issuing and
receiving calls).
In case of loss or
theft of the terminal, we will also proceed by notifying the provider to
disable the data on the eSIM card that we had in said terminal. It will be
advisable to have saved the information that our provider has sent us about the
eSIM that we want to cancel, for faster identification and cancellation of said
eSIM.
The case of wanting to
change the terminal and keep our number is also covered. Since
the terminal software itself allows deleting the data from the eSIM card (after
several confirmations) and once deleted we can proceed to load the same data
from the eSIM card in the new terminal that we want to use (again it will be
convenient to have saved the information of the provider on our eSIM since
there we will have the QR code or the necessary data to be able to record them
in the new terminal).
Although this new eSIM card was
already launched in 2016 by the GSMA, as of today it has not yet fully
deployed. Not all operators support eSIM and those that do do not support
it for any device. So it will not be strange to see in the coming years
hybrid terminals that have a 'nanoSIM' card slot and also have an integrated
eSIM card chip until the implementation is fully completed. These
terminals will be able to work with one or the other card indistinctly (and in
this case it is possible to have both plans activated just like a terminal with
dual SIM).