epmp capacity planner guide r2 - shelby broadbandfiles.shelbybb.com/cambium/epmp/epmp capacity...

1

ePMP Capacity Planner Guide

Release 2.1

2

ePMP Series introduction The purpose of this document is to provide a quick description on how to use the ePMP Capacity

Planner. The Cambium Networks ePMP Series is a wireless access system designed to create a radio

local area network (RLAN) through microwave links in a point‐to‐multipoint (PMP) mode or a point‐to‐

point (PTP) mode operating in the 2.4 and 5 GHz unlicensed bands. The ePMP Capacity Planner can offer

a quick help to determine the expected performances in terms of distances of an ePMP Series system

operating in line‐of‐sight (LOS), near line‐of‐sight (nLOS) or non line‐of‐sight (NLOS) propagation

condition according to the configuration of several system parameters like channel bandwidth and

antenna selection.

The ePMP System creates a point‐to‐multipoint or a point‐to‐point wireless broadband connection

transmitting a radio signal with OFDM modulation and MIMO transmission technique.

OFDM (Orthogonal Frequency Division multiplexing) is a multi‐carrier radio signal modulation based on

the subdivision of the broadband channel into orthogonally‐positioned subcarriers, each of which is

modulated based on a conventional modulation scheme. With the OFDM technique, a very high data

rate can be obtained increasing the system’s spectrum efficiency.

The following are the subcarriers modulation schemes which can be used by the ePMP System:

• QPSK

• 16‐QAM

• 64‐QAM

Each modulation supports multiple coding rates. For example 64‐QAM supports coding rates 5/6, 3/4

and 2/3.

The OFDM channel bandwidth can be configured with one of two possible values: 20 MHz and 40 MHz.

40 MHz channel bandwidth configurations allow for greater connection capacity as the signal occupies a

larger portion of the spectrum. The narrower channel bandwidth (20 MHz) increases reception

sensitivity and allows for more opportunities to operate in spectrum‐constrained RF environments.

The channel bandwidth must be configured with the same values in both the AP and SM modules of the

ePMP System.

MIMO (Multiple Input Multiple Output) radio transmission offers the capability of increasing the

capacity of a radio connection by transmitting and receiving parallel signals on separate Tx/Rx chains.

When the benefits of the MIMO techniques are combined with OFDM signaling and high system gain,

operators can achieve a highly robust radio connection in conditions of non‐line‐of‐sight (NLOS)

propagation. The ePMP System uses 2x2 MIMO with two radio receivers and two transmitters in both

the AP module and the SM module, transmitting in both directions two radio signals in the same

frequency. One signal is vertically polarized and the other signal is horizontally polarized, with dual

stream mode: the system transmits two distinct parallel data flows – one by way of the vertically

polarized radio signal and the other by way of the horizontally polarized radio signal. In this way, the

ePMP System doubles its transmission capacity.

The ePMP system also offers a single stream mode, in which both transmit chains transmit the same

data, which is then combined at the receiver. This mode improves the sensitivity of the system and

increases the range.

Cambium Networks offers two sector antennas to be used with the AP module of the ePMP System to

create the RF coverage of service areas in multisector sites. The antennas provided by Cambium

Networks are specifically designed to optimize the performance in terms of radio coverage of the ePMP

System:

3

• 90° sector antenna for sites with up to 4 AP modules

• 120° sector antenna for sites with up to 3 AP modules

Types of connections The ePMP Series can provide LOS (Line‐Of‐Sight) connectivity, nLOS (near Line‐Of‐Sight) connectivity and

NLOS (Non‐Line‐Of‐Sight) connectivity. A definition of these different propagation conditions are the

following.

• LOS: the optical line between the AP and the SM and the first Fresnel zone are clear.

• nLOS: the optical line between the AP and the SM is clear, but a portion of the first Fresnel zone is

blocked.

• NLOS: the optical line between the AP and the SM and a portion or even much of the first Fresnel zone

are blocked, but subsequent Fresnel zones are open.

Link budget calculation The link budget is the list of all the gains and losses that contribute to the propagation of the radio

frequency signal that travels from the transmitter to the receiver.

The parameters that are taken into account for the calculation of the link budget are described below:

Transmitter output power: the median power level of the transmitter in the transmission channel

expressed in dBm (relative to milliwatt). This level is configured for the AP transmitter by the regulatory

limits and is automatically adjusted in the SM transmitter through ATPC (Automatic Transmit Power

Control) functionality in order to get the maximum value.

Cable loss: the loss expressed in dB associated with the coaxial cable used to connect the transmitter

with the antenna. The loss typically depends on the length of the cable and its quality.

Transmitter antenna gain: assuming that the transmitter antenna main axis is oriented in the direction

of the receiver antenna, the maximum gain given in dB declared by the manufacturer is used.

4

EIRP (Effective Isotropic Radiated Power): is the sum of the transmitter output power and transmitter

antenna gain minus the cable loss, expressed in dBm.

Receiver antenna gain: assuming that the receiver antenna main axis is oriented in the direction of the

transmitter antenna, the maximum gain given in dB declared by the manufacturer is used.

Fade margin: the amount of power given in dB that represents the difference between the median

signal level at the receiver input and the receiver sensitivity. When the link fades exceeding the fade

margin an outage occurs. Fade margin must be selected by the user according to the link availability

target that must be met.

Receiver sensitivity: the minimum median signal level needed at the input of the receiver to achieve a

receiver output quality specific to a particular modulation scheme. Higher order modulation schemes

require higher quality receiver output and higher received power signal levels.

System Gain: the difference, expressed in dB, between the EIRP and the lowest order modulation

receiver sensitivity and cable loss. It conventionally refers to the minimum of the uplink and downlink

system gains and represents the maximum FSPL achievable with a particular system configuration.

FSPL (Free Space Path Loss): it represents the radio frequency propagation calculation used in the tool

and is the attenuation between the transmitter antenna and the receiver antenna in free‐space given by

the Friis formula:

FSPL [dB] = 32.44 + 20logf + 20logd

Where f is expressed in MHz and d is expressed in kilometers

FSPL [dB] = 36.6 + 20logf + 20logd

Where f is expressed in MHz and d is expressed in miles

This link budget calculation can be considered a valid approximation for LOS propagation in flat fading

conditions where the operating bandwidth is less than the coherence bandwidth of the radio channel

that is when the same degree of fading affects all frequencies of the signal bandwidth. In case the radio

channel is experiencing frequency‐selective fading effect the LOS range results may not be valid.

5

LINK BUDGET The user interface of the LINK BUDGET tab is divided into three main parts: System Configuration, Link

Budget and Coverage and Capacity.

6

SYSTEM CONFIGURATION In the SYSTEM CONFIGURATION menu the fields in green represent the parameters that can be set by

the user according to the system configuration that is applied to the ePMP system. The fields in white

are output values to be used as references for the input parameters setting.

The reference values are the following:

Lower frequency: lower edge of the selected frequency band

Upper frequency: upper edge of the selected frequency band

AP EIRP limit: limit of the combined power emitted by the AP antenna system, as defined by the

regulatory selected. A value of "‐" indicates that no limit is defined by the regulatory region selected.

Max AP Tx Power (max MCS): upper limit of the combined power that can be applied to the AP antenna

system, in order to be compliant to the EIRP limit. If the selected regulatory does not restrict the EIRP,

this is the upper limit of the combined power that can be applied to the AP antenna system at the

highest MCS level.

SM EIRP limit: limit of the combined power emitted by the SM antenna system, as defined by the

regulatory selected. A value of "‐" indicates that no limit is defined by the regulatory region selected.

Max SM Tx Power (max MCS): upper limit of the combined power that can be applied to the SM

antenna system, in order to be compliant to the EIRP limit. . If the selected regulatory does not restrict

the EIRP, this is the upper limit of the combined power that can be applied to the AP antenna system at

the highest MCS level.

Max range limit: minimum of maximum range calculated using the configuration parameters input in

the tool and limit of the ePMP product. The unit of the range is miles or kilometers as explained below.

The values that can be configured are the following:

Region: selection of the regulatory set of rules to be applied according to the country of operation.

7

Frequency band: selection of the 5GHz spectrum band (5.1 GHz, 5.2 GHz, 5.4GHz or 5.7/5.8GHz) or 2.4

GHz spectrum band. Not all frequency bands are available in all regions.

Fade Margin: setting of the margin on signal fading that the user wants to introduce in order to obtain

the desired link availability.

The following table summarizes the estimated fade margin for a certain link availability.

Link availability Fade margin

in LOS

Fade Margin

in nLOS

Fade Margin

in NLOS (suburban)

Fade Margin

in NLOS (urban)

90% 0 dB 2.5 dB 4 dB 7.5 dB

99% 2 dB 4.5 dB 9 dB 17 dB

99.9% 5 dB 6.5 dB 16 dB 27 dB

99.99% 8 dB 9 dB 24 dB 37 dB

Channel Bandwidth: selection of the width of the operating channel (20MHz or 40MHz).

AP type: selection of the type of radio used at the AP site (connectorized or integrated). Typically the AP

is a connectorized radio with a sector antenna, and the SM is an integrated radio. However, the Capacity

Planner gives the option of selecting any type of radio on either side, in case a PTP link is established.

8

For example, a PTP link can be configured with two integrated radios or with two connectorized radios

with small beamwidth antennas.

AP antenna system: selection of the antenna used for the AP module (90° sector antenna, 120° sector

antenna or 3rd party). The 90° and the 120° sector antennae are provided by Cambium. Selecting “3rd

party” in this field allows the user to input the parameters of any other antenna that is being used.

This field is valid only if the AP type is selected as Connectorized.

AP 3rd party antenna gain: input field of AP antenna gain if the AP antenna system is selected as “3rd

party”

AP 3rd party antenna cable loss: input field of AP antenna cable loss if the AP antenna system is selected

as “3rd party”

3rd party connectorized SMs in sector?: Answer “Yes” if any of the SMs deployed in the sector that is

being configured is connectorized.

RegionFrequency band 5.7/5.8 [GHz]

Fade Margin 0 [dB]Channel Bandwidth 20 [MHz]

AP typeAP antenna system

AP 3rd party antenna gain 25 [dBi]AP 3rd party antenna cable loss 1 [dB]

3rd party

Others

Connectorized

9

3rd party conn. SM antenna gain: input field of SM antenna gain if any connectorized SMs are deployed

in the sector. This field is valid only if the 3rd party connectorized SMs in sector? is selected as “Yes”.

3rd party conn. SM antenna cable loss: input field of SM antenna cable loss if any connectorized SMs are

deployed in the sector. This field is valid only if the 3rd party connectorized SMs in sector? is selected as

“Yes”.

Environment: type of propagation environment. The options for this field are: LOS, near LOS, NLOS

(suburban) or NLOS (urban).

The following table summarizes the excess path loss used in the range calculation formula for each

selection of the Environment parameter.

Environment Excess Path Loss

LOS 0 dB

nLOS 5 dB

NLOS (suburban) 15 dB

NLOS (urban) 25 dB





3rd party connectorized SMs in sector?3rd party conn. SM antenna gain 23 [dBi]

3rd party conn. SM antenna cable loss 1 [dB]

Others

Connectorized

Yes

Cambium 90° sector

10

Range unit: unit for ranges used throughout the tool. Choices are miles or kilometers.

Max range: distance between the AP and the location of the farther SM the user wants to serve with the

AP. The potential maximum cell size is calculated using other link budget parameters selected in the

green cells and is shown as the Max range limit. If the Maximum range input is larger than the Max

range limit an error message appears. The Max range limit is a reference value and cannot be changed.

The unit for the Max range and the Max range limit is either miles or kilometers, depending on the

Range unit selection.

With a smaller cell size, a larger percentage of users can use higher order modulation, and the sector

capacity is higher. On the other hand, with smaller cells network planning becomes very important, in

order to limit interference between sectors using the same frequency.

11

Number of SMs/sector: Number of SMs connected to one AP in one sector. The number of SMs affects

the throughput that can be achieved in a sector, and also the scheduling latency within the AP.

The maximum number of SMs that can be connected in one sector is 120. If a larger number is input in

this field, an error message appears.

If only one SM per sector is selected, it is assumed that this is a PTP link.

Duty cycle: Percentage of frame time dedicated to downlink (AP to SM) transmission / percentage of

frame time dedicated to uplink (SM to AP). The options are 75/25, 50/50 and 30/70.

In the ePMP system, the selected duty cycle does not necessarily translate to the same ratio of DL/UL

throughput. The reason is that the UL resources dedicated to data transmission vary according to the

number of SMs in the sector, because each SM is periodically polled.

12

Max Combined AP Tx power (min MCS): maximum power transmitted by both transmit chains at the

lowest MCS level. This field can be used to limit the Tx power to go beyond a certain value when

Country is selected as “Others”, as explained in the DOWNLINK AND UPLINK BUDGET section. If the

Country is not selected as “Others”, then this field is not used.

Interference measured?: Select “Yes” if the system experiences interference. Otherwise select “No”.

SM antenna for measuring interference: Antenna type used at the SM to measure the DL interference

level. This field is valid only if Interference measured? field is selected as “Yes”. The options in the drop‐

down menu depend on the frequency band selected.

13

Downlink interference level: Value (in dBm) of the interference being measured in the downlink

channel currently used (co‐channel). This field is valid only if the Interference measured? field is

selected as “Yes”.

Uplink interference level: Value (in dBm) of the interference being measured in the uplink channel

currently used (co‐channel). This field is valid only if the Interference measured? field is selected as

“Yes”.

14

Both the LINK BUDGET section and the COVERAGE AND CAPACITY section display results for one of the

available SM antenna types. The SM antenna type the user wants to display is selected in the SM

antenna for displaying data field. The options available in the drop‐down menu depend on the

frequency band selected.

LINK BUDGET In the LINK BUDGET part of the user interface the settings of all the parameters included in the link

budget calculation are listed in two columns: one for the downlink direction (from AP to SM) and one for

the uplink direction (from SM to AP) for the SM with antenna type selected in the SM antenna for

displaying data field. This section also shows the Carrier‐to‐Interference‐and‐Noise‐Ratio (CINR) values

both for the DL and the UL.

Both the sensitivity and CINR values are listed for all the MCS levels supported (MCS15 to MCS 9, in

addition to MCS1). The modulation and coding rate corresponding to each MCS level is also shown in

this section.






3rd party conn. SM antenna cable loss 1 [dB]Environment

Range unitMax range 10 [mi]

Number of SMs/sectorDuty cycle

Max Combined AP Tx power (min MCS) 30 [dBm]Interference measured?

SM antenna for measuring interferenceDownlink interference level -98 [dBm]

Uplink interference level -98 [dBm]

miles

Others

LOS

3050/50

Connectorized

Yes

YesINTEGRATED

Cambium 90° sector

15

The AP Tx Power per chain and the SM Tx power per chain are shown for the most robust modulation

and coding level (MCS15). In FCC and ETSI regions, this value is also the Tx power per chain at any other

modulation level, because the Tx power is limited by regulatory requirements.

When the Country in the SYSTEM CONFIGURATION section is selected as “Others”, the Tx power level is

increased at lower modulation and coding levels. The reason is that at lower modulation levels the

system can tolerate a higher level of EVM (error vector magnitude) on the constellation, because the

constellation points are farther apart. For example, in the 5.7/5.8 GHz band the transmit power is equal

to 20 dBm per chain at MCS15, but it goes up to 22 dBm per chain at MCS14, all the way to 30 dBm per

chain at MCS1. If the user does not want the Tx power to increase, it can limit it using the field Max

Combined AP Tx power in the SYSTEM CONFIGURATION section. If a value lower than 30 dBm is input

in this field, the Tx power will be limited by this value at any modulation mode.

When the system experiences interference and “Yes” is selected in the Interference measured? field in

the SYSTEM CONFIGURATION section, the noise floor of the system increases according to the

interference levels, and the DL/UL receive sensitivities for all MCS levels change. With higher

interference levels a stronger signal is needed at the receiver to achieve the same MCS level.

The effect of co‐channel interference is a reduction of the potential range for each MCS level as shown

in the COVERAGE AND CAPACITY section. This results in a number of SMs not being able to connect if

the maximum range was set as equal to the maximum potential range, or in the average capacity

decreasing because fewer SMs can use higher MCS levels.

The SYSTEM GAIN is reported for every modulation scheme in both the downlink and the uplink

directions. The table includes a note highlighting the eventual amount of imbalance of the System Gains

that can be useful to reconfigure the system.

Note that the calculations are performed with sensitivity values with one decimal point precision, but

both the sensitivity values and the gain values are shown as integer numbers.

COVERAGE AND CAPACITY In the COVERAGE AND CAPACITY section of the user interface the results of the link budget calculation

are shown for the SM with antenna type selected in the SM antenna for displaying data field.

SM antenna for displaying data

AP Tx Power per chain (MCS15) 20 [dBm] 0.100 [Watts] 20 [dBm] 0.100 [Watts]

AP Cable Loss 1 [dB] 0.001 [Watts] SM Cable Loss 0 [dB] 0.001 [Watts]AP Antenna Gain 15.0 [dBi] 13.0 [dBi]

Combined AP EIRP 37 [dBm] 5.012 [Watts] 36 [dBm] 4.0 [Watts]-68 [dBm] 64QAM 5/6 MCS15 -68 [dBm] 64QAM 5/6 MCS15-70 [dBm] 64QAM 3/4 MCS14 -70 [dBm] 64QAM 3/4 MCS14-72 [dBm] 64QAM 2/3 MCS13 -72 [dBm] 64QAM 2/3 MCS13-76 [dBm] 16QAM 3/4 MCS12 -77 [dBm] 16QAM 3/4 MCS12-80 [dBm] 16QAM 1/2 MCS11 -80 [dBm] 16QAM 1/2 MCS11-83 [dBm] QPSK 3/4 MCS10 -83 [dBm] QPSK 3/4 MCS10-86 [dBm] QPSK 1/2 MCS9 -85 [dBm] QPSK 1/2 MCS9-88 [dBm] QPSK 1/2 SS MCS1 -87 [dBm] QPSK 1/2 SS MCS130 [dB] 64QAM 5/6 MCS15 30 [dB] 64QAM 5/6 MCS1528 [dB] 64QAM 3/4 MCS14 28 [dB] 64QAM 3/4 MCS1426 [dB] 64QAM 2/3 MCS13 26 [dB] 64QAM 2/3 MCS1322 [dB] 16QAM 3/4 MCS12 21 [dB] 16QAM 3/4 MCS1218 [dB] 16QAM 1/2 MCS11 18 [dB] 16QAM 1/2 MCS1115 [dB] QPSK 3/4 MCS10 15 [dB] QPSK 3/4 MCS1012 [dB] QPSK 1/2 MCS9 13 [dB] QPSK 1/2 MCS910 [dB] QPSK 1/2 SS MCS1 11 [dB] QPSK 1/2 SS MCS1

SM Cable Loss 0 [dB] 0.001 [Watts] 1 [dB] 0.001 [Watts]SM Antenna Gain 13.0 [dBi] 15.0 [dBi]

Total DL Gain (MCS15) = 115 [dB] 115 [dB]Total DL Gain (MCS14) = 119 [dB] 119 [dB]Total DL Gain (MCS13) = 123 [dB] 123 [dB]Total DL Gain (MCS12) = 130 [dB] 131 [dB]Total DL Gain (MCS11) = 134 [dB] 134 [dB]Total DL Gain (MCS10) = 137 [dB] 137 [dB]

Total DL Gain (MCS9) = 140 [dB] 139 [dB]Total DL Gain (MCS1) = 142 [dB] 141 [dB]

The link is uplink limited by 1 dB

LINK BUDGET FOR INTEGRATED ANTENNA

SYSTEM GAINYes

AP Rx Sensitivity

Connectorized

Total UL Gain (MCS15) =Total UL Gain (MCS14) =Total UL Gain (MCS13) =Total UL Gain (MCS12) =Total UL Gain (MCS11) =Total UL Gain (MCS10) =

Total UL Gain (MCS9) =Total UL Gain (MCS1) =

Combined SM EIRP

AP Cable LossAP Antenna Gain

SM CINR AP CINR

SM Rx Sensitivity

DOWNLINK BUDGET (AP to SM)

Connectorized

SM Tx Power per chain (MCS15)

SM Antenna Gain

INTEGRATED

Yes

UPLINK BUDGET (SM to AP)

16

This section shows the expected range, the expected maximum DL, UL and total throughput, the sector

capacity, the latency, and a plot summarizing coverage and capacity results.

The DL/UL Potential Range represent, for each modulation scheme, the maximum distance at which the

radio link can operate with the selected configuration and fade margin. Values of range in red indicate

that the potential range is larger than the maximum range set in the Max range field in the SYSTEM

CONFIGURATION section.

The DL/UL/Total Max Throughput is the Downlink/Uplink/Total capacity of the sector assuming all the

registered SMs are operating at that modulation.

The DL/UL/Total Capacity is the Downlink/Uplink/Total capacity of the sector, taking into account the

percentage of users using each modulation, under the assumption that the users are evenly distributed

in the covered area and that they all generate the same amount of traffic. The capacity of the sector is

calculated as a proportion of the peak capacity taking into account the AP antenna pattern and the fact

that the users are evenly distributed in the covered area.

The covered area is limited by the Max range field set in the SYSTEM CONFIGURATION section.

Appendix A shows an example of capacity calculations.

The DL/UL/Total scheduling latency (in ms) shows the time needed at the AP to schedule all the SMs

connected in the sector, and it depends on the number of SMs set in the SYSTEM CONFIGURATION

section. This is less than the total latency the system experiences, which depends on additional factors.

The plot in the COVERAGE AND CAPACITY section shows the range of communication that can be

achieved with each modulation and coding level in the downlink, up to the maximum range set in the

Max range field in the SYSTEM CONFIGURATION section.

The plot in the COVERAGE AND CAPACITY section shows the range of communication that can be

achieved with each MCS level, up to the maximum range set in the Max range field in the SYSTEM

CONFIGURATION section. If some MCS levels cover an area outside the Max range field, those MCS

levels are not used. The legend of the plot indicates which MCS levels are not used, together with the

peak DL/UL/Total throughput for each used MCS level.

17

NETWORK PLANNING The network planning tab calculates the total number of enterprise and/or residential customers that

can be supported in a sector, given a selected distribution of plans.

In the NETWORK CONFIGURATION section the fields in white cannot be changed, and they are a

summary of the selections and the results in the LINK BUDGET section. The fields in green in the

NETWORK CONFIGURATION section are populated by the user.

Downlink %: percentage of frame time allocated to the downlink (AP to SM). This field corresponds to

the Duty cycle field in the SYSTEM CONFIGURATION section of the LINK BUDGET tab.

Max Cell Size: distance (in miles or kilometers) between the AP and the location of the farther SM the

user wants to serve with the AP. This field corresponds to the Max range field in the SYSTEM

CONFIGURATION section of the LINK BUDGET tab.

% Integrated SMs, % SMs with ePMP FORCE, % SMs with Reflector and % 3rd party conn SMs:

percentage of SMs using an integrated antenna, ePMP FORCE 100, Reflector, or a 3rd party

connectorized antenna respectively. The % Integrated SMs field is calculated from the others, to give a

sum of 100%.

Each percentage cannot exceed the limit shown in the Max % field for each type, which is calculated

using the parameters selected in the LINK BUDGET tab.

Ent. Oversubscription rate: oversubscription rate selected for the enterprise customers

Res. Oversubscription rate: oversubscription rate selected for the residential customers

Avg DL/UL Capacity: downlink/uplink capacity of the sector, taking into account the percentage of users

using each modulation and the percentage of SMs using each antenna system.

The assumption is that SMs with antenna types with higher gain are deployed farthest from the AP,

while SMs with antenna types with lower gain are deployed closests to the AP.

18

In the 5 GHz band there are four options: integrated, ePMP Force, reflector and 3rd party connectorized

SMs. Considering four concentric rings centered at the AP (where each ring can have area equal to zero

if the corresponding percentage is zero), the innermost circle includes the locations of all SMs using an

integrated antenna. The outer three rings include the locations of all SMs using the EPMP Force, the

reflector or a 3rd party connectorized antenna, with order depending on the gain of the 3rd party

connectorized antenna.

If for example the 3rd party connectorized antenna gain is higher than the gain of the ePMP Force, then

the order of the rings (starting from the AP) is: integrated, reflector, ePMP Force and 3rd party

connectorized.

In the 2.4 GHz band there are three options: integrated, reflector and 3rd party connectorized SMs.

Considering three concentric rings centered at the AP (where each ring can have area equal to zero if

the corresponding percentage is zero), the innermost circle includes the locations of all SMs using an

integrated antenna. The outer two rings include the locations of all SMs using reflector antenna or a 3rd

party connectorized antenna, with order depending on the gain of the 3rd party connectorized antenna.

For example, if the 3rd party connectorized antenna gain is higher than integrated antenna gain but

lower than the reflector gain, the order of the rings (starting from the AP) is: integrated, 3rd party

connectorized, and reflector.

The distribution of the SM antenna types in the sector is shown by the plot.

Avg Tot Capacity: sum of Avg DL Capacity and Avg UL Capacity.

Enterprise and Residential Plans There are three types of plans. Plan A is an enterprise plan; plan B is a residential plan and plan C is a

blended plan, with a mix of enterprise and residential customers. Both the Enterprise and the

Residential plans comprise of a mix of plans with different Downlink/Uplink throughputs. The cells in

green are populated by the user, indicating the Downlink/Uplink throughputs for each plan and the

distribution (in percentage) for each plan.

For plans A and B:

Average DL Throughput/user: average downlink throughput needed by the enterprise or residential

customers with the mix of plans selected by the user. This is the weighted average of the four DL plans

using the Average Distribution values as weights.

Average UL Throughput/user: average uplink throughput needed by the enterprise or residential

customers with the mix of plans selected by the user. This is the weighted average of the four UL plans

using the Average Distribution values as weights.

SM antenna type distribution ePMP Force 100

Connectorized

Reflector

Integrated

19

DL Users/sector: number of users that can be supported in the sector satisfying the downlink

requirements, taking into account the oversubscription rate. This is the Avg DL capacity divided by the

average DL Throughput/user and multiplied by the oversubcription rate.

UL Users/sector: number of users that can be supported in the sector satisfying the uplink

requirements, taking into account the oversubscription rate. This is the Avg UL capacity divided by the

average UL Throughput/user and multiplied by the oversubcription rate.

Total Users/sector: lower number between the DL Users/sector and the UL Users/sector. If parameters

are selected so that the DL Users/sector and the UL Users/sector are close, then the total capacity of

the sector is fully utilized.

Plan C is a mix of plans A and B with a certain percentage selected by the user.

In this case, the Average DL Throughput/user is the weighted average of the Average DL

Throughput/user for the enterprise and residential customers, and the Average UL Throughput/user is

the weighted average of the Average UL Throughput/user for the enterprise and residential customers.

The DL Users/sector and the UL Users/sector are again calculated as the Avg DL capacity and the Avg

UL capacity divided by the Average DL Throughput/user and the Average UL Throughput/user

respectively, multiplied by the corresponding oversubscription rate.

DL Users/sector =FLOOR(Avg DL Capacity/(Enterprise % × Enterprise Average DL Throughput/user /

Enterprise oversubscription rate + Residential % × Residential Average DL Throughput/user / Residential

oversubscription rate)

UL Users/sector =FLOOR(Avg UL Capacity/(Enterprise % × Enterprise Average UL Throughput/user /

Enterprise oversubscription rate + Residential % × Residential Average UL Throughput/user / Residential

oversubscription rate)

The Total Users/sector is again the lower number between the DL Users/sector and the UL

Users/sector.

If the Total Users/sector in any of the three sections exceeds the Number of SMs per sector parameter

configured in the LINK BUDGET section, the Total Users/sector cells become red to indicate the error.

In this case, the Number of SMs per sector parameter configured in the LINK BUDGET section has to be

increased.

If the Number of SMs per sector parameter is much higher than the Total Users/sector calculated in the

NETWORK PLANNING section, the user may want to reduce the Number of SMs per sector parameter

because the maximum throughput is calculated using an unnecessarily large number of SMs.

Appendix B shows an example of calculations of number of Enterprise and Residential users.

20

SECTOR THROUGHPUT The SECTOR THROUGHPUT CALCULATOR allows the user to either input the exact location of all the

SMs or to input the percentage of SMs that communicate at each MCS level.

In the SUBSCRIBERS’ LOCATIONS section the user inputs the values in the green cells:

‐ the distance between the AP and each SM

‐ the type of SM antenna system

Any number of SMs can be input, up to the maximum supported by the sector, which is 120 SMs. A

blank cell indicates that the corresponding SM is not used.

DL MCS: modulation and coding level that can be supported in the downlink direction by the SM at the

distance input by the user

UL MCS: modulation and coding level that can be supported in the uplink direction by the SM at the

distance input by the user

DL Throughput: peak downlink throughput supported by the SM at the MCS level indicated in the DL

MCS field

UL Throughput: peak uplink throughput supported by the SM at the MCS level indicated in the UL MCS

field

Total Throughput: sum of DL Throughput and UL Throughput.

SMs per DL modulation: number and percentage of SMs that can communicate in the downlink

direction in each of the MCS levels, based on the distances input for each SM and the SM antenna

selection.

SMs per UL modulation: number and percentage of SMs that can communicate in the uplink direction in

each of the MCS levels, based on the distances input for each SM and the SM antenna selection.

DL Average capacity: downlink capacity of the sector, taking into account the percentage of users

communicating at each MCS level, under the assumption that the users are distributed in the covered

SM number SM type DL MCS UL MCS

DL Throughput

[Mbps]

UL Throughput

[Mbps]

Total Throughput

[Mbps]

DL/UL/Total Throughput per

modulation [Mbps]


SM [Mbps]SM 1 0.5 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 MCS15 23 76.7% MCS15 23 76.7% 25.1/16.96/42.06 1.09/0.74/1.83SM 2 0.8 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 MCS14 0 0.0% MCS14 1 3.3% 0/0.74/0.74 0/0.74/0.74SM 3 0.4 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 MCS13 3 10.0% MCS13 3 10.0% 3.27/2.21/5.49 1.09/0.74/1.83SM 4 0.3 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 MCS12 4 13.3% MCS12 3 10.0% 4.37/2.21/6.58 1.09/0.74/1.83SM 5 1.8 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 MCS11 0 0.0% MCS11 0 0.0% 0/0/0 0/0/0SM 6 0.6 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 MCS10 0 0.0% MCS10 0 0.0% 0/0/0 0/0/0SM 7 2.0 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 MCS9 0 0.0% MCS9 0 0.0% 0/0/0 0/0/0SM 8 1.8 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 MCS1 0 0.0% MCS1 0 0.0% 0/0/0 0/0/0SM 9 1.6 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 Total 30 Total 30SM 10 0.6 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4SM 11 0.5 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 DL Average Capacity [Mbps] 32.74SM 12 0.4 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 UL Average Capacity [Mbps] 22.12SM 13 1.8 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 Total Average Capacity [Mbps 54.87SM 14 1.1 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4SM 15 1.4 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4SM 16 1.6 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4

SM 17 1.6 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4SM 18 0.1 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4SM 19 0.4 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4SM 20 0.7 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4SM 21 10.0 [mi] INTEGRATED MCS12 MCS12 25.2 18.3 43.5SM 22 6.8 [mi] INTEGRATED MCS12 MCS12 25.2 18.3 43.5 MCS15 10 33.3% MCS15 9 30.0% 9.82/6.64/16.46 1.09/0.74/1.83SM 23 5.6 [mi] INTEGRATED MCS13 MCS13 34.2 22.2 56.4 MCS14 8 26.7% MCS14 7 23.3% 7.64/5.16/12.8 1.09/0.74/1.83SM 24 5.0 [mi] INTEGRATED MCS13 MCS13 34.2 22.2 56.4 MCS13 5 16.7% MCS13 5 16.7% 5.46/3.69/9.14 1.09/0.74/1.83SM 25 6.0 [mi] INTEGRATED MCS12 MCS13 25.2 22.2 47.4 MCS12 3 10.0% MCS12 3 10.0% 3.27/2.21/5.49 1.09/0.74/1.83SM 26 3.8 [mi] INTEGRATED MCS13 MCS14 34.2 26.4 60.6 MCS11 2 6.7% MCS11 3 10.0% 3.27/2.21/5.49 1.09/0.74/1.83SM 27 0.6 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 MCS10 2 6.7% MCS10 2 6.7% 2.18/1.47/3.66 1.09/0.74/1.83SM 28 1.0 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 MCS9 0 0.0% MCS9 1 3.3% 1.09/0.74/1.83 1.09/0.74/1.83SM 29 1.6 [mi] INTEGRATED MCS15 MCS15 43.2 28.2 71.4 MCS1 0 0.0% MCS1 0 0.0% 0/0/0 0/0/0SM 30 6.2 [mi] INTEGRATED MCS12 MCS12 25.2 18.3 43.5 Total 30 Total 30SM 31 [mi] SM 32 [mi] 25.74SM 33 [mi] 15.58SM 34 [mi] 41.32SM 35 [mi] SM 36 [mi]

INPUT SMs DIRECTLY

DL Average Capacity [Mbps]UL Average Capacity [Mbps]Total Average Capacity [Mbps

ePMP SECTOR THROUGHPUT CALCULATOR

SM distance SMs per DL modulation

Cambium Networks confidential, not commercially bindingSUBSCRIBERS' LOCATIONS

SMs per UL modulation



modulation [Mbps]


SM [Mbps]SMs per DL modulation

21

area as indicated in the SUBSCRIBERS’ LOCATION section and that they all generate the same amount of

traffic.

Calculations for determining this field are done in the same way described in Appendix A.

UL Average capacity: uplink capacity of the sector, taking into account the percentage of users

communicating at each MCS level, under the assumption that the users are distributed in the covered

area as indicated in the SUBSCRIBERS’ LOCATION section and that they all generate the same amount of

traffic.

Calculations for determining this field are done in the same way described in Appendix A.

Total Average capacity: sum of DL Average capacity and UL Average capacity.

DL/UL/Total Throughput per modulation: downlink/uplink/total throughput assigned to each

modulation. This is the product of the DL/UL/Total Average capacity and the % of SMs per DL/UL

modulation.

DL/UL/Total Throughput per SM: downlink/uplink/total throughput each SM in each modulation group

will experience, assuming all SMs are active at the same time. Note that for all MCS levels that are in use

in the sector these values are the same for all SMs. The reason is that it is assumed all SMs generate the

same amount of traffic, and therefore they are allocated the same throughput, regardless of the MCS

level they can use for communication.

INPUT SMs DIRECTLY If the user does not want to input the distances of the SMs one by one, and they have the statistics of

the SMs distances available, the INPUT SMs DIRECTLY section can be used.

In this section the user can directly input the number of SMs for each MCS level (green cells) for the

downlink and uplink.

The DL/UL/Total Average Capacity calculations, the DL/UL/Total Throughput per modulation and the

DL/UL/Total Throughput per SM calculations are performed as explained above, but using the numbers

directly input by the user instead of using the SMs distances.

When using the SUBSCRIBER LOCATIONS’ section or the INPUT SMs DIRECTLY section, verify that the

total number of SMs in the sector matches the Number of SMs/sector in the LINK BUDGET tab. The

number of SMs/ sector affects the available throughput, so if the numbers do not match a wrong

throughput number is used in the calculations in this tab.

MCS15 10 33.3% MCS15 9 30.0% 9.82/6.64/16.46 1.09/0.74/1.83MCS14 8 26.7% MCS14 7 23.3% 7.64/5.16/12.8 1.09/0.74/1.83MCS13 5 16.7% MCS13 5 16.7% 5.46/3.69/9.14 1.09/0.74/1.83MCS12 3 10.0% MCS12 3 10.0% 3.27/2.21/5.49 1.09/0.74/1.83MCS11 2 6.7% MCS11 3 10.0% 3.27/2.21/5.49 1.09/0.74/1.83MCS10 2 6.7% MCS10 2 6.7% 2.18/1.47/3.66 1.09/0.74/1.83MCS9 0 0.0% MCS9 1 3.3% 1.09/0.74/1.83 1.09/0.74/1.83MCS1 0 0.0% MCS1 0 0.0% 0/0/0 0/0/0Total 30 Total 30

25.7415.5841.32

INPUT SMs DIRECTLY

DL Average Capacity [Mbps]UL Average Capacity [Mbps]Total Average Capacity [Mbps



modulation [Mbps]


SM [Mbps]SMs per DL modulation

22

References All the detailed informations about Cambium Networks ePMP Series can be found in the official product

documentation available for download from Cambium Networks public website:

http://www.cambiumnetworks.com/products/epmp

Questions/Comments [email protected]

23

Appendix A Example of aggregate capacity calculation

In the aggregate capacity calculation two assumptions are made:

‐ The SMs are geographically evenly distributed in the covered area

‐ All SMs generate the same amount of traffic

The input values used in this example are the following:

These are the steps for calculating the aggregate capacity:

‐ The Potential DL Range for each modulation is limited by the Max range field in the SYSTEM

CONFIGURATION section

Example with Max range set at 10 miles.

MCS level Potential range Actual range

MCS15 2.30 miles 1.45 miles



MCS12 12.91 miles 10 miles










SM antenna for measuring interferenceDownlink interference level 0 [dBm]

Uplink interference level 0 [dBm]

SM antenna for displaying data

Others

LOS

3050/50

Connectorized

Yes

NoINTEGRATED

INTEGRATED

Cambium 90° sector

miles

24





‐ Calculate the area (in square miles) covered with each modulation

The modulation and coding level supported by each SM in LOS conditions depends on the

distance between the AP and the SM. SMs closer to the AP can support higher MCS levels, while

SMs farther from the AP can only support lower modulation levels.

This figure shows the area covered by the AP and the eight rings corresponding to one of the

MCS levels supported by the ePMP system.

Assuming a 90° sector antenna at the AP, the areas covered by the AP at each modulation level

are shown in the next table.

MCS level Area (square miles) Area (%)

MCS15 4.14 5.27%

MCS14 6.57 8.37%

25

MCS13 15.40 19.61%

MCS12 52.39 66.74%

MCS11 0 0%

MCS10 0 0%

MCS9 0 0%

MCS1 0 0%

The area calculated for MCS levels 11 to 1 is equal to 0, because the sector under consideration

is limited at 10 mile range, so the assumption is that there are no users (and therefore no area

covered) beyond 10 miles.

The same table also shows the percentage of the total area (within the 10 mile range) covered

with each modulation. Since all SMs are assumed to be evenly distributed in the covered area,

these percentages also represent the percentages of SMs communicating at each of the MCS

levels.

Similar calculations are made for the uplink case.

‐ Calculate the DL time and the UL time allocated for each MCS level

The time in the DL and UL subframes is divided among SMs (and therefore MCS levels)

proportionally to the percentage of users communicating at each MCS level. The following table

shows the DL and UL times which are calculated as

DL (UL) time for MCS X = % area for MCS X / DL (UL) throughput for MCS X

MCS level DL time (s) UL time (s)

MCS15 0.001220 0.002068

MCS14 0.002215 0.003353

MCS13 0.005735 0.010078

MCS12 0.026485 0.034394

MCS11 0.000000 0.000000

MCS10 0.000000 0.000000

MCS9 0.000000 0.000000

MCS1 0.000000 0.000000

‐ Calculate the DL, UL and total capacity

The DL (UL) peak capacity is the inverse of the sum of the DL (UL) times allocated for each MCS.

The peak capacity is then multiplied by a factor (equal to 85%) to take into account the AP

antenna pattern and the fact that the users are evenly distributed in the covered area.

26

DL (UL) capacity = 1/sum of all DL (UL) times per MCS * antenna factor

The total capacity is simply the sum of the DL and UL capacities.

DL Capacity = 23.8 Mbps

UL Capacity = 17.0 Mbps

Total Capacity = 40.9 Mbps

27

Appendix B

Example of calculation of Number of Enterprise and Residential Users Let us assume the following configuration parameters:

As shown in the figure, SMs closer to the AP utilize an integrated antenna, while SMs farther from the

AP utilize either one of the types of connectorized antenna.

With these configuration parameters the resulting capacities are:

The plans offered to enterprise customers are:










SM antenna for measuring interferenceDownlink interference level 0 [dBm]

Uplink interference level 0 [dBm]

Others

LOS

3050/50

Connectorized

Yes

NoINTEGRATED

Cambium 90° sector

miles

32.0 Mbps22.1 Mbps54.0 Mbps

Avg UL capacityAvg DL capacity

Avg Tot capacity

28

The plans offered to residential customers are:

Downlink Uplink Average

Distribution 4.0 Mbps 1.0 Mbps 10%

15.0 Mbps 5.0 Mbps 20% 20.0 Mbps 10.0 Mbps 50% 30.0 Mbps 15.0 Mbps 20%

For plans A (Enterprise) and B (Residential):

Average DL Throughput/user

Enterprise Average DL Throughput/user = 3 Mbps × 25% + 5 Mbps × 50% + 10 Mbps × 20% + 20 Mbps ×

5% = 6.25 Mbps

Residential Average DL Throughput/user = 4 Mbps × 10% + 15 Mbps × 20% + 20 Mbps × 50% + 30 Mbps

× 20% = 19.40 Mbps

Average UL Throughput/user

Enterprise Average UL Throughput/user = 3 Mbps × 25% + 5 Mbps × 50% + 10 Mbps × 20% + 20 Mbps ×

5% = 6.25 Mbps

Residential Average UL Throughput/user = 1 Mbps × 10% + 5 Mbps × 20% + 10 Mbps × 50% + 15 Mbps ×

20% = 9.10 Mbps

DL Users/sector

Enterprise DL Users/sector = FLOOR(32.0 Mbps/6.25 Mbps × 5) = 25

Residential DL Users/sector = FLOOR(32.0 Mbps/19.40 Mbps × 15) = 24

UL Users/sector

Enterprise UL Users/sector = FLOOR(22.1 Mbps/6.25 Mbps × 5) = 17

Residential UL Users/sector = FLOOR(22.1 Mbps/9.10 Mbps × 15) = 36

Total Users/sector

Enterprise Total Users/sector = min(25,17) = 17

Residential Total Users/sector = min(24,36) = 24

Parameters are selected efficiently if the number of DL Users/sector is approximately equal to the

number of UL Users/sector, so that no downlink or uplink resources remain unutilized.

Plan C is a mix of plans A and B with a certain percentage selected by the user.

For this example the percentages of plans A and B are both 50%.

Average Distribution

3.0 Mbps 3.0 Mbps 25%5.0 Mbps 5.0 Mbps 50%

10.0 Mbps 10.0 Mbps 20%20.0 Mbps 20.0 Mbps 5%

Downlink Uplink

29

DL Users/sector = FLOOR(32.0 Mbps/(50% × 6.25 Mbps / 5 + 50% × 19.40 Mbps / 15) = 25

UL Users/sector = FLOOR(22.1 Mbps/(50% × 6.25 Mbps / 5 + 50% × 9.10 Mbps / 15) = 23

Total Users/sector = min(25,23) = 23

In this case, the total numbers of users calculated for the Enterprise plans (17 users), for the Residential

plans (24 users) and for a blended plan (23 users) are all lower than the Number of SMs/sector

parameters configured in the SYSTEM CONFIGURATION section in the LINK BUDGET tab.

epmp capacity planner guide r2 - shelby broadbandfiles.shelbybb.com/cambium/epmp/epmp capacity...

Documents