- This topic has 60 replies, 1 voice, and was last updated 2 years, 3 months ago by Lemaure.
25th February 2009 at 09:03 #55921MKTGuest
Well friends……Pix & HSH
What i understood from your posts is that one MAL is better option then three MAL…….
actually no one is better then other both are same………
The only point to be worried about is the radio load(??). All that you have to keep in mind is that radio load should never be more then 50%.???
Iam sorry……but i disagree with the concept.
contd……..25th February 2009 at 10:16 #55922MKTGuest
GSM networks are interference limited.
Techniques like Frequency hopping and power control are introduced in GSM networks to counter the problem of interference.
UPLINK Interference is something difficult to control.
It will occur when ,the two MS, in two different cells , transmits at same frequency, at same time.
The technique hopping, with associated terms such as MAL,MAIO,HSN…can provide a significant relief to interference.
Added with it, the power control mechanism will also have a soothing effect.
But, in spite of all these measures the 100 percent elimination of interference is not guaranteed.
So, we can always try to minimize the interference.In this direction…
I raised a subject…that the option of having 3 MAL in comparison to 1 MAL is better or not?
I say, it is better to have 3 MAL’s.
See, if there are three neighbors..A,B,C.
The MAL1, MAL2, MAL3 are allocated to A, B and C respectively.
In this scenario…the condition
MS transmits, at same ARFCN, at same time,
will have probability equals to zero.
So, isn’t this is a better choice?
regards25th February 2009 at 10:47 #55923HSHGuest
I understand what did you meant,
realy I never thought about uplink as you did; yes but as I said before you will phase more limitation, and I already used both without getting big diffrence in quality performance!! after I did a comparison of drive test result and statistics (Uplink)! but there was great benefit in TRX configuration,
regards25th February 2009 at 11:53 #55924PixGuest
I already gave the conditions in which you should use 1×3 or 1×1:
1×1 or 1×3, which one gives the best utilisation ? Well, it’s about the same !!
30 freq in 1×1, with load = 12% –> 3.6 TRX / cell max
3 x 10 freq in 1×3, with load = 30%
–> 3.3 TRX / cell max
The main question is about your radio design:
large overlaps, heterogeneous terrain, hills, overshooting, reflections, high antennas –> prefer 1×3
sharp cell coverages, good downtilt, homogeneous terrain, regular inter-site distance, regular antenna azimuths –> you can use 1×1.
The better is 1×1, because it shares ALL frequencies at once. So any improvement on the radio design gives great results immediately, in terms of QoS and capacity. Also, it is easier to manage after a while.25th February 2009 at 12:35 #55925HSHGuest
Great discussion already done between us and already transferred all of our best information about SFH,
let us discuss the advantage and disadvantage of MRP type of freq. plan with a consideration that we already implemented all of necessary of Optimization actions (general Network),
regards25th February 2009 at 13:13 #55926ISTGuest
‘but the main benefit of MAIO is to avoid interference between Cell A and other cells in the same site (Cells B & C); is just giving starting frequency in the MAL,’
You can give different HSN for different cell of the same site to avoid interference.
To my understanding,MAIO is used to avoid interference among the different TRX of the same cell.Because all the TRX in that cell is using the same MAL and same HSN,so different starting position will avoid interference between them.
Let me correct if I am wrong.25th February 2009 at 18:15 #55927PixGuest
IST, consider a BTS:
3 sectors, all synchronized.
1×1 –> all sectors use same freuency
same HSN + different MAIO –> each cell will NEVER use the same frequency as its 2 neighbors.
Excellent choice, isn’t it ?
Now, for 1×3 (with non adjacent freq among the 3 MA lists) or different HSN, then you’re right, the MAIO doesn’t change anything.25th February 2009 at 20:59 #55928ISTGuest
yes ı definitely agree with you.
But what will happen for the case 1X1, if we use same MAIO but Different HSN for the cells of the same site?
Will there be interference among them?25th February 2009 at 21:36 #55929PixGuest
You have to read my post until the end, and very carefully 🙂
“Now, for 1×3 (with non adjacent freq among the 3 MA lists) or different HSN, then you’re right, the MAIO doesn’t change anything.”
The “or” is important.
So yes, different HSN and same MAIO is possible, but less efficient25th February 2009 at 22:57 #55930ISTGuest
I missed the ‘or’ 🙂 in your previous reply :(:-(26th February 2009 at 07:38 #55931HSHGuest
nice point you meant;
– Was better if you meant(1*1 or 1*3) and (Space or sequence)? I’m sure that there were friends didn’t got your idea well.
– Mr. pix already answered with our respect.
– I can not see the benefit for using different HSN in the same Site, HSN plan will be impossible if you wanted to do for big Cities (Sometime you have 1000’s of cells in your plan); if there is! I appreciate if somebody explain?
Regards26th February 2009 at 11:13 #55932PixGuest
1 HSN for all sectors of one BTS
BTS A = HSN 1
BTS B = HSN 2
and so on.
Now, if two cells that are quite distant then they can use the same HSN, it’s OK.27th February 2009 at 09:53 #55933BobGuest
If I have 36 frequencies and each MA list is 12 frequencies with 1*3 frequency planning which strategy give me good result if the MA list start consecutive(1,2,3,,,,,) or (1,3,5,,,,,) as example27th February 2009 at 18:39 #55934PixGuest
MAL1 = 1, 2, 3…12
MAL2 = 13, 14, 15, …
MAL3 = 24, 25, 26, …
this should give the best result. however, they might be worse than BBH 🙂5th March 2009 at 06:51 #55935ProGuest
1.I have 1-9 frequency for hopping(1*1). What is the maximum capcity i can use in each site.
2.Shall i use MAIO:0, MAIO:4 and MAIO:8 for the above mentioned frequencies to aviod the adjcency collision with unique HSN.
Suggest me if i am wrong…