LTE Base Station Site:
Field
Description
Transmitter type
Set the transmitter type to Intra-network (Server and interferer). If you want to consider the transmitter only as an interferer, set the type to Inter-network (Interferer only). No coverage for an interferer only transmitter will be calculated for coverage predictions and it will not serve any mobile in Monte Carlo simulations. Under Transmission/Reception, you can see the total losses and the noise figure of the transmitter. Atoll calculates losses and noise according to the characteristics of the equipment assigned to the transmitter. Equipment can be assigned using the Equipment Specifications dialogue which appears when you click the Equipment button
Transmission/Reception
Equipment Specifications
The equipment you select and the gains and losses you define are used to initialize total transmitter losses in the uplink and downlink: - TMA: TMA: You can select a tower-mounted amplifier (TMA) from the list.. Feeder: You can select a feeder cable from - Feeder: the list..
- Transmitter equipment: You can select transmitter equipment from the Transmitter list. - Feeder length: You can enter the feeder length at transmission and reception. - Miscellaneous losses: You can enter miscellaneous losses at transmission and reception. The value you enter must be positive.
Cell Description Name
Layer
Frequency band
By default, Atoll names the cell after its transmitter, adding a suffix in parentheses. If you change transmitter name, Atoll does not update the cell name. You can enter a name for the cell, but for the sake of consistency, it is better to let Atoll assign a name. If you want to change the way Atoll names cells, see the Administrator Manual . The number of the coverage layer to which the cell belongs. This value is automatically assigned when you create a new cell, but you can modify it afterwards. The layer is used during calculations to select the serving cell. For more information on the cell layer selection options, The cell’s frequency band from the frequency band list.
Channel number:
The number of the channel from the list of available channels.
Channel allocation status:
The status of the current channel allocated to the cell: - Not allocated: The current channel has neither been allocated automatically nor manually. The AFP considers that a Not
allocated channel is modifiable without cost. - Allocated: The current channel has been allocated automatically or manually. The AFP considers that an Allocated channel is modifiable but only if absolutely necessary.
Physical cell ID
- Locked: The current channel has been allocated automatically or manually. The AFP considers that a Locked channel is not modifiable. The physical cell ID of the cell. It is an integer value from 0 to 503. The physical cell IDs are defined in the 3GPP specifications. There are 504 unique physical-layer cell identities. The physical cell IDs are grouped into 168 unique cell ID groups (called SSS IDs in Atoll), with each group containing 3 unique identities (called PSS IDs in Atoll). An SSS ID is thus uniquely defined by a number from 0 to 167, and a PSS ID is defined by a number from 0 to 2. Each cell’s reference signals transmit a pseudo-random sequence corresponding to the physical cell ID of the cell. Physical cell IDs also indicate the subcarriers being used for reference signal transmission in the downlink. Reference signal hopping, or vshifting, is the calculation of the index of the subcarrier being used for reference signal resource elements. The v-shifting index is calculared as (PCI)Mod 6 for single-antenna transmitters and as (PCI)Mod 3 for multiantenna transmitters.
• PSS ID: The PSS ID corresponding to the current physical cell ID. This value is determined automatically from the physical cell ID. • SSS ID: The SSS ID corresponding to the current physical cell ID. This value is determined automatically from the physical cell ID. • Physical cell ID status: The status of the physical cell ID currently assigned to the cell:
- Not allocated: The current physical cell ID has neither been allocated automatically nor manually. The AFP considers that a Not allocated physical cell ID is modifiable without cost. - Allocated: The current physical cell ID has been allocated automatically or manually. The AFP considers that an Allocated physical cell ID is modifiable but only if absolutely necessary. - Locked: The current physical cell ID has been allocated automatically or manually. The AFP considers that a Locked physical cell ID is not modifiable. • Physical cell ID domain: The physical cell ID domain to which the allocated physical cell ID belongs. This and the reuse distance are used by the AFP for physical cell ID allocation. • Reuse distance: The minimum reuse distance after which the channel or physical cell ID assigned to this cell can be assigned to another cell by the AFP.
For more information on the AFP, see "Configuring Network Parameters Using the AFP". • Max power (dBm): The cell’s maximum transmission power. You can enter or modify this value if the RS EPRE option under the Advanced options on the Global Parameters tab of the LTE Network Settings folder’s Properties dialogue is set to any of the following:
- Calculated (equal distribution of unused EPRE) - Calculated (with boost): This option corresponds to a 3 dB boost in the RS EPRE with 2 transmission antenna ports and 6 dB boost with 4 ports. - Calculated (without boost) - Independent of max power The transmission powers corresponding to different channels are calculated using Max power, the energy per resource element offsets defined for the SS, PBCH, PDSCH, and PDCCH, and the number of resource elements corresponding to each channel, all of which are also calculated by Atoll. Max power is calculated by Atoll from the user-defined RS EPRE value if the RS EPRE option in the Global Parameters of the LTE Network Settings folder is set to User-defined. • RS EPRE (dBm): The reference signal energy per resource element. You can enter or modify this value if the RS EPRE option under the Advanced options on the Global Parameters tab of the LTE Network Settings folder’s Properties dialogue is set to User-defined or Independent of max power.
This value is calculated by Atoll from the user-defined max power value if the RS EPRE option under the Advanced options on the Global Parameters tab of the LTE Network Settings folder’s Properties dialogue is set to any of the following: - Calculated (equal distribution of unused EPRE) - Calculated (with boost): This option corresponds to a 3 dB boost in the RS EPRE with 2 transmission antenna ports and 6 dB boost with 4 ports. - Calculated (without boost) For more information, see "The Global Network Settings". • SS EPRE Offset/RS (dB): The difference in the energy of a resource element belonging to the synchronisation signals with respect to the energy of a reference signal resource element. This value is used to calculate the transmission power corresponding to the primary and secondary synchronisation signals (PSS, SSS). • PBCH EPRE Offset/RS (dB): The difference in the energy of a resource element belonging to the PBCH with respect to the energy of a reference signal resource element. This value is used to calculate the transmission power corresponding to the physical broadcast channel (PBCH). • PDCCH EPRE Offset/RS (dB): The difference in the energy of a resource element belonging to the PDCCH with respect to the energy of a reference signal resource element. This value is used to calculate the transmission power corresponding to the physical downlink control channel (PDCCH). • PDSCH EPRE Offset/RS (dB): The difference in the energy of a resource element belonging to the PDSCH with respect to the energy of a reference signal resource element. This value is used to calculate the transmission power corresponding to the physical downlink shared channel (PDSCH).
Atoll first calculates the energy per resource element corresponding to the reference signal resource elements, the SS, PBCH, PDSCH, and PDCCH. Once the energies available for each of these resource element types are known, they are converted into transmission powers for further calculations. In the offset fields above, you have to enter the offsets, i.e., the difference in the energy levels, for one resource element of each type. For example, if a resource element belonging to the SS has 3 dB less energy than a resource element of the downlink reference signals, you should enter -3 dB in the SS EPRE Offset. Atoll will then calculate the actual transmission power of the SS, i.e., all the resource elements of the SS, from this offset and the number of SS resource elements per frame. • Instantaneous RS power (dBm): The instantaneous reference signal transmission power calculated from the maximum power or RS EPRE and the EPRE offsets.
• Instantaneous SS power (dBm): The instantaneous SS transmission power calculated from the maximum power or RS EPRE and the EPRE offsets. • Instantaneous PBCH power (dBm): The instantaneous PBCH transmission power calculated from the maximum power or RS EPRE and the EPRE offsets. • Average PDCCH power (dBm): The average PDCCH transmission power calculated from the maximum power or RS EPRE and the EPRE offsets. • Average PDSCH power (dBm): The average PDSCH transmission power calculated from the maximum power or RS EPRE and the EPRE offsets. If the cell’s transmitter has smart antenna equipment assigned to it, the transmission powers of
the cell increase by (in dB), where n is the number of antenna elements of the smart antenna. This gain in transmission powers is referred to as the AAS power combining gain. • Min RSRP (dBm): The minimum RSRP required for a user to be connected to the cell. The RSRP is compared with this threshold to determine whether or not a user is within the cell’s coverage or not. • Reception equipment: You can select the cell’s reception equipment from the reception equipment list. For more information, see "Defining LTE Reception Equipment". • Scheduler: The scheduler used by the cell for bearer selection and resource allocation. You can select the scheduler from the list of schedulers available in the Schedulers table. For more information see "Defining LTE Schedulers". • Max number of users: The maximum number of simultaneous connected users supported by the cell. • No. of users (DL): The number of users connected to the cell in the downlink. This can be user-defined or an output of Monte Carlo simulations. • No. of users (UL): The number of users connected to the cell in the uplink. This can be userdefined or an output of Monte Carlo simulations. • TDD frame configuration: The frame configuration used by the cell when the cell’s frequency band is TDD. If the network’s switching point periodicity is set to "Half Frame", you can select a frame configuration of type DSUUU-DSUUU, DSUUD-DSUUD, DSUDD-DSUDD, or DSUUUDSUUD. If the network’s switching point periodicity is set to "Frame", you can select a frame configuration of type DSUUU-DDDDD, DSUUD-DDDDD, or DSUDD-DDDDD. For more information on TDD switching point periodicity, see "The Global Network Settings".
• Diversity support (DL): The type of antenna diversity technique (transmit diversity, S U-MIMO, AMS, or AAS) supported by the cell in downlink. You cannot select more than one type of MIMO technique (transmit diversity, SU-MIMO, or AMS) at a time. • Diversity support (UL): The type of antenna diversity technique (none, receive diversity, SUMIMO, AMS, or MU-MIMO) supported by the cell in uplink.
Specific calculations are performed (and gains applied) for terminals supporting AAS and MIMO. • AMS & MU-MIMO threshold (dB): For AMS, it is the reference signal C/N or C/(I+N) threshold, according to the option set in the Advanced parameters ("The Global Network Settings"), for switching from SU-MIMO to Transmit or receive diversity. For MU-MIMO, it is the minimum required reference signal CNR for using MU-MIMO. For more information on Adaptive MIMO switching, see "Multiple Input Multiple Output Systems". • MU-MIMO capacity gain (UL): The uplink capacity gain due to multi-user (collaborative) MIMO. This can be user-defined or an output of Monte Carlo simulations. In uplink throughput coverage predictions, the cell capacity will be multiplied by this gain on pixels where M U-MIMO is used. • Fractional power control factor: This factor is used for path loss compensation when performing fractional power control on the uplink. For example, if this factor is set to 0.8, only 80% of the actual path loss will be considered when estimating the received power. Therefore, the received power from any mobile on the uplink will be estimated to be higher than it would actually be (using 100% of the path loss), which will be interpreted by the mobile as a need to
reduce its transmission power. This factor is represented by in 3GPP specifications. This factor represents the influence of the serving cell on the fractional power of any mobile. • Max PUSCH C/(I+N) (dB): This value is used for power control on the uplink. The difference between the Max PUSCH C/(I+N) and the uplink noise rise of the cell corresponds to the nominal PUSCH power for the cell. The nominal PUSCH power is a cell-specific parameter from which a limit on the uplink transmission powers of mobiles in the cell can be extracted. This
factor is represented by in 3GPP specifications. Max PUSCH C/(I+N) is updated during uplink noise rise control in Monte Carlo simulations based on the maximum noise rise constraints of the neighbouring cells. • Interference coordination support: The type of inter-cell interference coordination (ICIC) technique supported by the cell. You can select Static DL or Static UL. With ICIC, a cell uses a third of the channel bandwidth in its ICIC part of the frame. Which third of the channel bandwidth is used by the cell depends on its PSS ID. Therefore, fractional frequency planning can be performed by the AFP by allocating physical cell IDs. For more information, see "Planning Physical Cell IDs".
• ICIC configuration: The inter-cell interference coordination (ICIC) configuration used by the cell in downlink and uplink. ICIC configuration defines the numbers of frequency blocks available in the ICIC parts of the frames when the cell supports Static DL or Static UL inter-cell interference coordination. For more information, see "Defining ICIC Configurations". • ICIC delta path loss threshold (dB): The maximum difference between the path loss of the second best server and the path loss of the best server to be considered at cell edge. Cell edge mobiles are served by the ICIC part of the LTE frame, i.e., the part of the frame that uses a fraction of the channel bandwidth. • Max traffic load (DL) (%): The downlink traffic load not to be exceeded. This limit can be taken into account during Monte Carlo simulations. If the cell traffic load is limit ed by this value, the cell will not be allowed to have a downlink traffic load greater than this maximum. • Traffic load (DL) (%): The downlink traffic load percentage. This can be user-defined or an output of Monte Carlo simulations. • ICIC ratio (DL) (%): You can set the percentage of the total downlink traffic load that corresponds to the ICIC part of the frame. For example, if the downlink traffic load is 80%, and you set the ICIC ratio to 50%, it means that 40% of the downlink traffic load is on the ICIC part of the frame while the other 40% is on the non-ICIC part. This can be user-defined or an output of Monte Carlo simulations. • Max traffic load (UL) (%): The uplink traffic load not to be exceeded. This limit can be taken into account during Monte Carlo simulations. If the cell traffic load is limited by this value, the cell will not be allowed to have an uplink traffic load greater than this maximum. • Traffic load (UL) (%): The uplink traffic load percentage. This can be user-defined or an output of Monte Carlo simulations. • UL noise rise (dB): The uplink noise rise in dB. This can be user-defined or an output of Monte Carlo simulations. This is the global value of uplink noise rise including the inter-technology uplink noise rise. • ICIC UL noise rise (dB): The uplink noise rise of the part of the LTE frame that uses a fraction of the channel bandwidth. This noise rise is only used when the ICIC support for the cell includes Static UL. This can be user-defined or an output of Monte Carlo simulations. • Max UL noise rise (dB): The upper limit on both uplink noise rise values, i.e., the UL noise rise and the ICIC UL noise rise. It is used for uplink noise rise control during Monte Carlo simulations. This parameter represents the maximum interference that a cell can tolerate on the uplink.
• Angular distributions of interference (AAS): The Monte Carlo simulation results generated for transmitters using a smart antenna. These results are the angular distributions of the downlink traffic power spectral density. • AAS usage (DL) (%): The total downlink traffic load that corresponds to the traffic loads of the users supported by the smart antenna. For example, if the downlink traffic load is 80%, and you set the AAS usage to 50%, it means that 40% downlink traffic load is supported by the smart antenna equipment while the other 40% is supported by the main antenna. AAS usage is calculated during Monte Carlo simulations, and cannot be modified manually because the AAS usage values correspond to the angular distributions of interference. • Inter-technology UL noise rise: This noise rise represents the interference created by mobiles and base stations of an external network on this cell on the uplink. This noise rise will be taken into account in all uplink interference-based calculations involving this cell in Monte Carlo simulations. It is not used in predictions where Atoll calculates the uplink total interference from the uplink noise rise which includes inter-technology uplink interference. For more information on inter-technology interference, see "Modelling Inter-technology Interference". • Inter-technology DL noise rise: This noise rise represents the interference created by mobiles of an external network on the mobiles served by this cell on the downlink. This noise rise will be taken into account in all downlink interference-based calculations involving this cell. For more information on inter-technology interference, see "Modelling Inter-technology Interference". • Max number of intra-technology neighbours: The maximum number of LTE neighbours that the cell can have. • Max number of inter-technology neighbours: The maximum number of other technology neighbours that the cell can have. • Neighbours: You can access a dialogue in which you can set both intra-technology and inter-
technology neighbours by clicking the Browse button ( neighbours, see "Planning Neighbours".
). For information on defining
