However, the best way - and always recommended - is to use network planning tools suitable for this purpose, as the AFP, from Optimi, or Ultima Forte, from Scheme. The concept of HSN and MAIO is important, and when the number of TRX and frequencies is small, we can even do planning ‘byt hand’. MAIO planning is straightforward if the number of TRX is small compared to the length of the sequence of hopping.įor example, MAY 0 means that the TRX should use the first frequency, or f1. It is the frequency that TRX uses so get hopping. It’s MAIO that designate the initial position of frequency - among the frequencies available in MA List, that list with the frequency hopping. Well, first defining MAIO: Mobile Allocation Index Offset. The size of the MA List should be taken into account in the planning of HSN: HSN should be the designated so as to minimize the average probability of collision, according to the designated MAIOs. In our example, the MA List is small - just three frequencies. And if the we have 1x1 SFH it is recommended to have the SAME HSN for ALL SECTORS of the BTS. When we enabled the Hopping - our case - all TRX in the SAME SECTOR has the SAME HSN. If HSN is greater than zero, then frequencies vary pseudo-randomly. If HSN is zero, the frequency hopping sequence is cyclic, ie without changes. It is a number that defines the frequency hopping algorithm, and can vary from 0 to 63, ie there are 64 hopping algorithms to be used in GSM. Sure, with the example in mind, let us return to our parameters.įirst, the definition of HSN: Hopping Sequence Number. The MA List with the channels of traffic then would be: To illustrate, let’s consider a sector with 4 TRX, where the first TRX is used for BCCH and the others are TCH TRX. MA List : set of frequencies (channels) assigned to a particular sector, ie are those channels that can be used to attend calls from users. To understand how HSN and MAIO are used in planning, we first need to know some brief concepts.įrequency Hopping – or FH : one of the great advantages of the GSM system, in the constant search to reduce interference. The main goal today is to understand, in a planning already deployed, what they mean values MAY HSN and assigns. Note: The goal here is not to teach HSN and MAIO planning, since this task involves many possible configurations and scenarios, which would escape the scope of our tutorial. It did not help? So come on and try to understand better … Quickly: The HSN is used to define the hopping sequence from one frequency list, and MAIO is used to set the initial frequency on this list. That’s right, HSN and MAIO are used in frequency planning of a GSM network, and know them well naturally will lead us to better results. The terms MAIO and HSN are also often used, but many people are confused about it’s planning. Today let’s understand what are the parameters MAIO and HSN in a GSM network.

Define malist