Summary of the invention
At above-mentioned prior art problems, the purpose of this invention is to provide the method that a kind of energy efficient balance mobile communication system service amount distributes, to improve the business load ability of system.
For achieving the above object, the technical solution used in the present invention is: the changing method that equalizing traffic distributes in a kind of mobile communication system, static traffic amount alarm line A, a dynamic service amount alarm line A ' and an alignment buffer P are set in this method each sub-district in system, and wherein A, A ' and P are the channel number that takies; When the traffic carrying capacity in the sub-district is higher than A '+P, trigger and switch, the business that is maximum traffic carrying capacitys P channel switches to the adjacent cell that traffic carrying capacity is lower than this sub-district, adjust A ' according to the relativeness of this sub-district and all adjacent cell traffic carrying capacitys and the actual effect of switching simultaneously, to reduce the alarm line of the high sub-district of traffic carrying capacity, unnecessary load is cut out rapidly, or raise the alarm line of the low sub-district of traffic carrying capacity, avoid unnecessary false-alarm.
The above-mentioned relativeness and the actual effect of switching according to this sub-district and all adjacent cell traffic carrying capacitys adjusted dynamic service amount alarm line A ' and carried out according to following method:
(1) calculates the traffic carrying capacity L (S) of this sub-district;
(2) whether judge L (S) more than or equal to A '+P, continue operation, otherwise continue following operation if change step (5);
(3) whether judge L (S) smaller or equal to A '-P,, otherwise finish the adjustment of this dynamic service amount alarm line A ' if continue following operation;
(4) A ' is adjusted into the maximum among the alarm line A of the traffic carrying capacity L (S) of this sub-district and this sub-district static traffic amount, finishes the adjustment of this dynamic service amount alarm line A ' then;
(5) calculate the traffic carrying capacity L (Ai) of all adjacent cells, wherein Ai representative any one adjacent cell wherein;
(6) judge whether that the traffic carrying capacity of this sub-district is minimum, if not, change step (8) and continue operation, otherwise continue following operation;
(7) promote the dynamic service alarm line A ' of this sub-district, be that A ' gets the minimum value between A '+d1 and M-P, finish the adjustment of this dynamic service amount alarm line A ' then, above-mentioned M is the maximum of traffic carrying capacity in this sub-district, d1 is a less rise amount, is the channel number;
(8) person that selects the handoff candidate;
(9) person that judges whether to find the handoff candidate if can not find, changes step (13) and continues operation, otherwise continues following operation;
(10) judge whether that the traffic carrying capacity of this sub-district is the highest or the number C of the candidate that finds greater than P, if not, change step (12) and continue following operation, otherwise continue following operation;
(11) reduce the A ' of this sub-district, promptly A ' gets the maximum between A '-d2 and A, and wherein d2 is a less downward modulation amount, also is the channel number;
(12) switch min (C, P) individual candidate change step (14);
(13) promote the dynamic service alarm line A ' of this sub-district, promptly A ' gets the minimum value between A '+d1 and M-P;
(14) finish.
Above-mentionedly select the handoff candidate person carry out according to following method:
(1) selects a calling;
(2) traffic carrying capacity that judges whether an adjacent cell is lower than this sub-district, if do not have, finishes the operation that this selects candidate, otherwise continues following operation;
(3) whether the level of judging the adjacent cell that satisfies traffic conditions satisfies following two conditions:
Level (Ai)>max (0, pa)+rxlevel_min (Ai) and
level(Ai)>level(s)+BS_TXPWR_MAX-bs_pwr(s)*2
Wherein:
Pa=MS_TXPWR_MAX(Ai)-MS_P
Level (Ai) is the descending level of the adjacent cell that arrives of moving table measuring
Rxlevel_min (Ai) is the minimum incoming level that switches to this adjacent cell requirement
MS_TXPWR_MAX (Ai) is the travelling carriage maximum transmission power of stipulating in the adjacent cell
MS_P is the maximum power capability of travelling carriage
Level (s) is the incoming level of the down direction of this sub-district
The maximum power that takes place in this sub-district of BS_TXPWR_MAX
Bs_pwr (s) finishes the operation that this selects candidate if the emitting power grade of this sub-district reality does not satisfy, otherwise determines that the calling of being selected is the handoff candidate person.
From the technical scheme of the invention described above as can be seen, the present invention is by being provided with the alarm line A of a static traffic amount in each sub-district, dynamic service amount alarm line A ' and an alignment buffer P, make when the traffic carrying capacity in the sub-district is higher than A '+P, trigger to switch maximum traffic carrying capacity P are switched to the adjacent cell that traffic carrying capacity is lower than this sub-district, regulate A ' according to the relativeness of this sub-district and all adjacent cell traffic carrying capacitys and the actual effect of switching simultaneously, unnecessary load is cut out rapidly.When local congestion appears in network, method of the present invention can the traffic carrying capacity of congested subnetwork to around the low weight adjacent cell of load spread step by step.Because adopted the method for the dynamic service amount alarm line that can regulate, business reorganization speed is fast, and the existence of alignment buffer P has been avoided because the frequent back and forth consequence of switching that the accidental fluctuation of traffic carrying capacity causes makes system more stable.
In a word, the invention has the advantages that following some:
(1) judgment condition of each cell-overload can dynamically be adjusted according to the relative Congestion Level SPCC of traffic carrying capacity between this sub-district and the adjacent cell, therefore can avoid the balancing procedure of false-alarm and quickening traffic carrying capacity.
(2) setting of alignment buffer P is even make network also frequent switching can not take place under the situation of overload.
(3) in the process of selecting the handoff candidate person, fully take into account the factor of wireless parameter, guaranteed the success of switching, can not rebound.
Embodiment
The present invention is suitable for a network under the BSC control.Local congested the time when occurring in the network, the wireless environment of congested sub-district worsens, and the interference between the user increases, and influence is conversation normally.Cover these regional base station overload operations this moment, systematic function descends.Because of the Radio Resource scarcity, network can't hold more user simultaneously.The effective ways that change this situation are under the prerequisite that does not influence the current talking quality, and some users are forced to switch to time congested sub-district from congested sub-district.If this switching causes new congested, so once more some travelling carriage of inferior congested sub-district is switched in the not congested sub-district.By this method of diffusion layer by layer, the distribution of the traffic carrying capacity between the balanced sub-district.But the prerequisite of doing like this is, requires overlappingly between the sub-district, and the user spatially is not very concentrated, otherwise even force to switch, travelling carriage causes switching unsuccessful or clear-cut call drop because do not measure effective adjacent cell.
BSC can pass through data of database, and relatively the height of traffic carrying capacity between the sub-district can determine the Target cell that whether switches and switch simultaneously according to specific circumstances.When decision was switched, the relation between the traffic carrying capacity of this sub-district and the adjacent cell traffic carrying capacity was with reference to figure 1~Fig. 3.The traffic carrying capacity of this sub-district is minimum among Fig. 1, and the warning of this moment is exactly a typical empty alarm, because unnecessary load can't cut out, for fear of the new void alarm of continuous generation, just needs to promote the dynamic alarm line A ' of this sub-district.The traffic carrying capacity of this sub-district is the highest among Fig. 2, and also will reduce the dynamic alarm line A ' of this sub-district this moment except needs cut out unnecessary travelling carriage, when the traffic carrying capacity of this sub-district promotes a little to some extent, will switch once more like this.Traffic carrying capacity is all lower than what fell last time after every generation is once switched in the sub-district, and because A ' descends, satisfying the speed of switching can be faster, and the speed of traffic carrying capacity decline just can be faster.The traffic carrying capacity of this sub-district is placed in the middle among Fig. 3, and this situation is the most common.Dynamically the adjustment of alarm line depend on handoff candidate person that institute can find how much.If the candidate that finds is less than P, central area and adjacent cell that the traffic carrying capacity that shows this sub-district concentrates on this sub-district have certain distance, and A ' remains unchanged in this case.If the candidate that finds is greater than or equal to P, show that so traffic carrying capacity is dispersed in the sub-district various piece in this sub-district, might switch and more calling, so reduce the dispersion process that A ' accelerates this cell business volume.If the person that do not find the handoff candidate proves that this is a false-alarm newspaper, show that the traffic carrying capacity in the sub-district is too concentrated, avoid the false-alarm newspaper so improve A '.
The present invention makes the calling of center cell switch to sub-district all around by the comparison of traffic carrying capacity and the adjustment of traffic carrying capacity alarm line.Concrete grammar is: static traffic amount alarm line A, a dynamic service amount alarm line A ' and an alignment buffer P are set in each sub-district in system, when the traffic carrying capacity in the sub-district is higher than A '+P, trigger and switch, maximum traffic carrying capacity P are switched to the adjacent cell that traffic carrying capacity is lower than this sub-district, adjust A ' according to the relativeness of this sub-district and all adjacent cell traffic carrying capacitys and the actual effect of switching simultaneously, to reduce the alarm line of the high sub-district of traffic carrying capacity, unnecessary load is cut out rapidly, or raise the alarm line of the low sub-district of traffic carrying capacity, avoid unnecessary false-alarm.
Above alarm line A, dynamic service amount alarm line A ' and the alignment buffer P of described static traffic amount all represent with the channel number that takies.
The alarm line A of described static traffic amount is a rational traffic carrying capacity that is provided with for each sub-district according to the bearing capacity of network and total user capacity, when traffic carrying capacity is lower than A, can trigger traffic carrying capacity and switch.
The traffic carrying capacity alarm line need be adjusted to A ' from A according to the concrete condition of the traffic carrying capacity of this sub-district and adjacent cell.The minimum value of A ' is A, and maximum is M-P, wherein largest traffic channel number in the M=sub-district.If the traffic carrying capacity alarm line immobilizes, so when the traffic carrying capacity of this sub-district and adjacent cell all than higher the time, the overload alarm exists always, but can not alleviate this situation effectively again, this can increase the burden of system.In fact traffic overload is a relative notion, when having only the adjacent cell that exists traffic carrying capacity to be lower than this sub-district, the traffic carrying capacity alarm of this sub-district is just meaningful, because have only during this time, unnecessary travelling carriage could be switched in the low weight adjacent cell of these loads the traffic carrying capacity between the balanced sub-district.So when the false-alarm newspaper appears in this sub-district, need upwards revise A '.Conversely,,, need downward revision A ', make this sub-district after a handoff procedure, very fast warning once more in order to accelerate the process of cutting out if this cell load is overweight.
When the user moves, fluctuation among a small circle can take place in the traffic carrying capacity of each sub-district, if require traffic carrying capacity to surpass just alarm of dynamic alarm line A ', this fluctuation among a small circle will be frequent the handoff procedure of triggering traffic carrying capacity, but this switching is not obvious again to the professional balanced effect of reality, and has strengthened the burden of system significantly.Therefore the buffering P of an alarm line need be set, and the traffic carrying capacity of regulation sub-district just can switch when exceeding A '+P, and can cut out P travelling carriage at most, does like this and has avoided the influence of fluctuation among a small circle, has improved the efficient of switching simultaneously.
When regulating dynamic alarm line A ', following situation can take place: the traffic carrying capacity in certain each sub-district, zone is soaring mutually, for fear of false-alarm, promotes A ' according to each sub-district of mentioned above principle mutually.But when the traffic carrying capacity of each sub-district began to descend again, according to current A ', no longer transshipped the sub-district, and the A ' of sub-district will no longer change, thereby make A ' lose the effect of alarm.The way that solves is, regulation, when the traffic carrying capacity L (S) in the sub-district is lower than dynamic alarm line A '-P, make A '=MAX (L (S), A).Like this, when the traffic carrying capacity of each sub-district descended, the A ' of each sub-district descending rapidly, really embodied the effect of alarm line.
By the adjustment of dynamic service amount alarm line A ', the trigger condition of traffic carrying capacity alarm is modified in the sub-district, and final purpose is to avoid the false-alarm newspaper or accelerate the speed that traffic carrying capacity is disperseed.Need to prove when the traffic carrying capacity in the sub-district when alarm line A is following, because not alarm so do not need to adjust A ', does not therefore start the adjustment process of A ' yet, only the traffic carrying capacity in the sub-district just starts the adjustment process of dynamic service amount alarm line A ' when alarm line A is above.
Dynamic service amount alarm line A ' realizes adjusting according to following method, with reference to figure 5: in step (1), calculate the traffic carrying capacity L (S) of this sub-district; Whether judge L (S) more than or equal to A '+P in step (2), if explanation need be carried out the traffic carrying capacity equalization operation, therefore need to change step (5) and continue operation, otherwise continue following operation; In step (3), whether judge L (S) smaller or equal to A '-P, if the traffic carrying capacity that shows the sub-district is descending, and therefore will continue following operation, otherwise because L (S) is between A '-P and A '+P, this is normal buffering area, action that need not be any.In fact just this buffering area has embodied characteristics of the present invention, and the too much traffic carrying capacity that causes of having avoided exactly fluctuating is among a small circle switched, and keeps the stability of system, therefore, finishes the adjustment of this dynamic service amount alarm line A ' this moment; In step (4), A ' is adjusted into the maximum among the alarm line A of the traffic carrying capacity L (S) of this sub-district and this sub-district static traffic amount, finishes the adjustment of this dynamic service amount alarm line A ' then; In step (5), calculate the traffic carrying capacity L (Ai) of all adjacent cells, wherein Ai representative any one adjacent cell wherein; In step (6), the traffic carrying capacity that judges whether this sub-district is minimum, if not, explanation can be carried out the traffic carrying capacity equalization operation, change step (8) and continue operation this moment, otherwise, the principle that shifts from high to lower with reference to traffic carrying capacity, this is a typical false-alarm, so should continue following operation to promote the A ' of this sub-district; In step (7), promote the A ' of this sub-district, promptly A ' gets the minimum value between A '+d1 and M-P, finishes the adjustment of this dynamic service amount alarm line A ' then, and above-mentioned M is the maximum of traffic carrying capacity in this sub-district, and d1 is a less rise amount, is the channel number; In step (8), the person's that selects the handoff candidate operation; In step (9), the person that judges whether to find the handoff candidate is if find, handover operation is arranged this moment certainly, therefore change step (10) and continue operation, otherwise, illustrate that this is a false-alarm, though show the traffic overload of sub-district, the user spatially may be more concentrated, is not suitable for cutting out, the person is not with regard to possible call drop, so there is not the action of switching, avoid false-alarm and need to promote A ', promptly A ' gets the minimum value between A '+d1 and M-P; In step (10), the number C of the candidate that judges whether that the traffic carrying capacity of this sub-district is the highest or find is greater than P, if not, illustrate that this cell business volume is placed in the middle, therefore need not to adjust A ', change step (12) and continue following operation, otherwise show that this sub-district not only transships, and unnecessary calling, so to continue the operation of following reduction A ' than being easier to switch; Reduce the A ' of this sub-district in step (11), promptly A ' gets the maximum between A '-d2 and A, and wherein d2 is a less downward modulation amount, also is the channel number.Because dynamically alarm line descends, this sub-district is more prone to produce the traffic carrying capacity alarm, thereby accelerates the speed that load disperses; In step (12), switch min ((C, P) minimum value between C and the P is got in expression to described min for C, P) individual candidate.
Above-mentionedly select the handoff candidate person realizes according to following method: the first step, at first select a calling; Second step judged whether that the traffic carrying capacity of an adjacent cell was lower than this sub-district, if do not have, finished the operation that this selects candidate, otherwise continued following operation; In the 3rd step, judge whether the level of the adjacent cell that satisfies traffic conditions satisfies following two conditions:
Level (Ai)>max (0, pa)+rxlevel_min (Ai) and
level(Ai)>level(s)+BS_TXPWR_MAX-bs_pwr(s)*2
Wherein:
Pa=MS_TXPWR_MAX(Ai)-MS_P
Level (Ai) is the descending level of the adjacent cell that arrives of moving table measuring
Rxlevel_min (Ai) is the minimum incoming level that switches to this adjacent cell requirement
MS_TXPWR_MAX (Ai) is the travelling carriage maximum transmission power of stipulating in the adjacent cell
MS_P is the maximum power capability of travelling carriage
Level (s) is the incoming level of the down direction of this sub-district
The maximum power that takes place in this sub-district of BS_TXPWR_MAX
Bs_Pwr (s) finishes the operation that this selects candidate if the emitting power grade of this sub-district reality does not satisfy, otherwise determines that the calling of being selected is the handoff candidate person.
Above-mentioned described condition of second step is the signal that the requirement travelling carriage has received enough adjacent cells, guarantees handover success, rather than returns old channel.
The signal strength signal intensity that above-mentioned described condition of the 3rd step is the adjacent cell that receives of requirement travelling carriage is higher than the incoming level on this cell downlink direction, and doing like this is to guarantee after successful switch, can not rebound at once.If do not satisfy this condition, travelling carriage is after switching to adjacent cell, generally spatially can not change a lot, travelling carriage just can be measured this original sub-district like this, the path loss that is present adjacent cell is that original adjacent cell is little than this sub-district, just automatically switch then, always destroyed the purpose that traffic carrying capacity is switched.In the handoff procedure of reality, the adjacent cell of power budget maximum can be come the foremost of switching target small area formation, to improve handover success rate.
From the condition of above-mentioned switching as can be seen, the traffic carrying capacity of sub-district switch not only and between the sub-district the relative height of traffic carrying capacity relation is arranged, also the spatial distribution with travelling carriage reality also has relation, do not switch so traffic carrying capacity switching of the present invention is not the pressure on the complete meaning, but the pressure under the prerequisite that guarantees communication quality is switched.Fig. 4 has described the characteristics of the distribution of traffic of two different overloaded cells, obviously the B sub-district is because objectively traffic carrying capacity is concentrated, dynamically alarm line A ' can be bigger, and the process that traffic carrying capacity is disperseed is slow, and the A sub-district is because objectively traffic carrying capacity is relatively disperseed, dynamically alarm line A ' is just lower, and the process that traffic carrying capacity is disperseed is than very fast.
Below by an example the present invention is described further.In this example, each parameter all is that the number with channel is a dimension.Wherein, the rise amount d1 of alarm line is defined as 1, and downward modulation amount d2 is defined as 2.With reference to figure 6.One has three sub-districts among Fig. 6, is mutual adjacent cell in twos, and the traffic model of these three sub-districts is represented with the parameter of following table:
| ?M | ?A | A’ | ?P | ?d1 | ?d2 |
Sub-district A | ?100 | ?70 | ?70 | ?4 | ?1 | ?2 |
Sub-district B | ?100 | ?70 | ?70 | ?3 | ?1 | ?2 |
Sub-district C | ?100 | ?70 | ?70 | ?4 | ?1 | ?2 |
Suppose that at initial time T0 the data of the traffic carrying capacity of three sub-districts and dynamic alarm line are as follows:
T0 | ?L | ?A’ |
Sub-district A | ?95 | ?95 |
Sub-district B | ?80 | ?80 |
Sub-district C | ?70 | ?70 |
Because traffic carrying capacity changes in the sub-district, can enter into the different step of Fig. 5 in the different moment respectively.With reference to figure 5.
T1 sub-district A constantly has 5 end of callings, L (A)=90.Because L (A)+P (A)<A ' is (A), enter step 4 among Fig. 5, A ' is (A)=90;
T1 sub-district C constantly has 1 travelling carriage to insert, and L (C)=71 because traffic carrying capacity is lower than all adjacent cells, enters step 7 among Fig. 5, and A ' (C)=71;
T2 constantly sub-district A has 4 travelling carriages to insert, L (A)=94 because L (A)=P (A)+A ' (A), found 4 handoff candidate persons, and, met the relation of Fig. 2 because the traffic carrying capacity of sub-district A is the highest, so enter step 11 among Fig. 5, A ' (A)=88 and switches and 4 travelling carriages.
T3 is the result that T2 changes constantly constantly, and wherein 1 travelling carriage switches to sub-district B, and 3 switch to sub-district C.Sub-district B is because in the buffer area, and A ' (B) remains unchanged, and sub-district C meets Fig. 1 because of traffic carrying capacity, so enter step 4 among Fig. 5, A ' (C)=74;
T4 constantly sub-district A has 2 travelling carriages to insert again because L (A)=A ' (A)+P (A), so enter step 11 among Fig. 5, A ' (A)=86 and switches and 4 travelling carriages.
T5 is the intermediate object program that T4 changes constantly constantly, and 2 travelling carriages switch to sub-district B, and 2 travelling carriages switch to sub-district C.Among the B of sub-district because L (B)=A ' (B)+P (B).But only find 2 candidates.So A ' (B) remains unchanged, but 2 travelling carriages with switching.Sub-district C is still because traffic carrying capacity meets Fig. 1, so A ' (C)=76;
T6 is the T5 result that sub-district B switches in the moment constantly.Sub-district C is because same reason makes A ' (C)=78;
T7 constantly has two travelling carriages to insert among the B of sub-district because L (B)=A ' (B)+P (B), so produce alarm, but because the person that can not find the handoff candidate, so there is not travelling carriage to be switched away;
T8 is the result that T7 changes constantly constantly, and sub-district B enters
step 13 among Fig. 5 because produce false-alarm, makes A ' (B)=81;
| A’/L(A) | A’/L(B) | A’/L(C) |
?T0 | ?95/95 | ?80/80 | ?70/70 |
?T1 | ?90/90 | ?80/80 | ?71/71 |
?T2 | ?90/94 | ?80/80 | ?71/71 |
?T3 | ?88/90 | ?80/81 | ?74/74 |
?T4 | ?88/92 | ?80/81 | ?74/74 |
?T5 | ?86/88 | ?80/83 | ?76/76 |
?T6 | ?86/88 | ?80/81 | ?78/78 |
?T7 | ?86/88 | ?80/83 | ?78/78 |
?T8 | ?86/88 | ?81/83 | ?78/78 |
By relatively going up the data of table moment T1 and T8, as can be seen, the traffic carrying capacity of sub-district A has descended, and dynamic service amount alarm line has also descended simultaneously.At this moment because the traffic carrying capacity of the traffic carrying capacity of sub-district A and adjacent cell is keeping the relation of Fig. 2 basically, and the user is more even in spatial distributions, always can find enough suitable handoff candidate persons, so when disperseing traffic carrying capacity, A ' accelerates this process by downward modulation.Though sub-district C has new calling incision or inserts, because the traffic carrying capacity of traffic carrying capacity and adjacent cell is keeping the relation of Fig. 1 basically, so constantly raise A ', has avoided meaningless false-alarm always.And the traffic carrying capacity of the traffic carrying capacity of sub-district B and adjacent cell has kept the relation of Fig. 3 basically, so the adjusting of A ' and the handoff candidate person's who is found is how much relevant.Found suitable candidate constantly at T5, but because do not exceed alignment buffer P, so A ' remains unchanged, and,, produced false-alarm, so A ' raises on the contrary because do not find candidate at moment T7.
The total dispersion direction of traffic carrying capacity is to flow to sub-district C from sub-district A by sub-district B.The calling that the calling of switching among the B of sub-district of not associating is not necessarily cut from the A of sub-district, this is travelling carriage to be arranged in the determining positions in space, another characteristics of the present invention have also been embodied, when seeking the handoff candidate person, taken into full account the factor of wireless parameter, guarantee handover success, and not bounce-back.
The result of this routine traffic carrying capacity adjustment is that the gradient of the traffic carrying capacity of each sub-district slows down under the prerequisite that guarantees communication quality, and the traffic carrying capacity of each sub-district is close gradually.