We with students received a task to explore the GEA3 encryption algorithm used in GPRS / EDGE.
During Communication MS and Base Station OSMOCOM (BS), we received a LLC message:
LLC Message (Ciphered): 01c00f1840623297a594ee196714a2653d23d5a2ac52792f0434
With the following the favoring parameters:
Cipher Algorithm: GEA3
KC_GPRS: A8FC3A996A80D000.
SAPI: 1.
Nu: 3.
IOV_UI: 0.
OC: 0.
After applying the GEA3 algorithm, we received a decrypted LLC message:
LLC message (decrypted): 01C00F0802012A0452F00300010017161805F4D7BF04CA 26176B

We obtain that the calculated FCS (6B1726) using the decrypted LLC message and the FCS (6B1726) contained in the LLC message are equal.

When communicating MS and the real BS, we received the following LLC message:
LLC Message (Ciphered) 41C00B9299A1EB51A1AD1FE71633786B23CBD8E6D41C9F658C89C9F658C89C9544AF2BAAC35
With the following the favoring parameters:
Cipher Algorithm: GEA3
KC_GPRS: 8F94A69C3D9BDF48.
SAPI: 1.
Nu: 2.
IOV_UI: 0x10000000 (Got From Xid)
OC: FROM 0 to 8388608
Therefore, we tried to apply OC parameter from 0 to 8388608 to decrypt the message (other parameters were not changed).
At each stage, we calculated the FCS and compared it with the FCS contained in the LLC message and did not have success.
Finally the question:
Can IOV_UI value (OSMOCOM BS: 0, Real BS: 0x10000000) influence the decoding, and if so, how ??

The village, where I live very strange in terms of radio frequencies of mobile operators.
All 4 operators on the same tower, all LTE B3 1800, a small village, approximately 2 km.
So here - in the internet premises there is no at home, in stores, anywhere. Only if in the window to laugh half.
Turning to the operators, they look at their cards and see a complete coating, but on the fact some holes.

You can stand and see your tower and the Internet gives a maximum of 5 megabits, and you can go far and catch a good speed, especially at night.
Or move away from the window at home half meter and all - no connection.
I would like to understand - how to move this question from a dead point? I have already called and invited specialists to measure signals - no sense. It is understandable.
It seems that the equipment is stupidly brought, stupidly fasten and that's it. Without measurements and without calculations and without checking results on the ground.

Hello wanted to ask a question local, the people put external antennas enhancing the signal coming on the modem / router, and why it is impossible to put a cellular amplifier / repeater of the desired range so that the router came a higher-quality signal and what will be the speed from this amplification, will MIMO work and Other buns? Who tried to think about this, is very interested in the opinion of people who understands?

Post has been editedPecaPit - 24.11.20, 01:11

Is there a 4G? How much are?

And because it is Palevo. Give pieces 5 for this repeater, you will turn on, leave the village all without communication, and then you will come uncle the cops and will be asked to turn it off politely and no longer turn on. You can send them away, but then a 300 thousand fine is possible, you can not send and turn on when you leave, but then they will come again and will already write out the penalty, then again the fine but more. Therefore, it is better to hang an antenna without any amplifiers.

So if you are going to buy, you need to approach this very thoroughly, in no case to buy a 3G repeater.

Operators are now actively launching various LTE, we have 800,1800,2600 will soon be 2300, in other cities there are 450. The most high-speed 1800. Less than 2600, very slow 800 and 450. 2300 have not been tested yet, but there will be even faster than 1800. So the amplifier must be taking a type of 1800-2300, and it is desirable to adjust the gain. Otherwise come.

Post has been editedanyone - 26.11.20, 17:36

This is not an aggregation called, as it is called I do not know, but the active mode can be from three BS.
The aggregation is included on one BS between all layers of the LTE that is on this BS. There is no aggregation between different BS.

Post has been editedanyone - 26.11.20, 17:41

Actually, there is. It is called Intersite Carrier Aggregation.
A typical example of such an aggregation at MTS in Moscow, when the Bands 3 + 7 + 38 are aggregated.
There are other examples of cross-site aggregation in Russia from different operators.

Post has been editedvvireless - 27.11.20, 03:23

Well, it is only in Moscow, or include centralized and we just do not know about it)

anyone
https://www.cnews.ru/n...agregatsiyu_nesushchih.

Well, we have no such.

But now LTE2300 is started, Band 40. Yes, all right to tele2 is the highest possible and high-quality comes out. MTS and megaphone in the span

Post has been editedanyone - 06.12.20, 17:21

And who can tell what is called and whether it is possible to take on the request of the authorities to the Location of a person on a mobile phone in two cases of Yu.
1. The first that when conversations for which basic ties clung the phone.
2.And the second if the calls were not but the phone was clinging for the basic tower ..
By such detail there is an opportunity in networks to determine the location of the person at the time of time.
After all, without conversations when the phone simply clings to a radio signal for the next three ties, the location of a person in is fixed in some detail and how is it the detailing called?

And no one knows the detailing and billing of 2017 is stored strictly until December 31, 20 years old!
Or until January 31, 21 years old?

anton99zel , Good afternoon, each antenna has an electro or mechanical RET (tilter), when planning and installing antennas, the specified slopes must be set. Very often they are not exhibited and the antennas simply look after the horizon instead of taking place to the bottom on the subscribers, especially if we. The item is located in the pit.