BusinessPhone Communication Platform 4.0
Installation Instruction ASB 150 02

## Integrated Cordless

The Integrated Cordless (IC) is a digital cordless telephone solution complying to the DECT standard providing wireless connection for up to 108 portables with the A-protocol and 210 portables in GAP-protocol applications in the cabinet BDV 113 08. Applications equipped with the cabinet BDV BS 101 0x are limited to 24 portables because only the IC-CU2 can be installed.

After the system has been physically installed use RASC and the Cordless System Manager (CSM) for initialization, maintenance, updating, fault finding and when possible to recover the PBX from errors. The CSM is orderable under LZYNB 201 01 R6A or higher for the A-protocol and LZYNB 201 05 R1B or higher for GAP applications.

### Board Descriptions

#### IC-Control Unit (IC-CU)

The IC-CU_ (only for the cabinet BDV 113 08) is the control board supporting the A-protocol and up to 7 IC-LUs can be installed in the same cabinet. Up to 56 BSs can be connected. The board offers 2 connections for:

- the Cordless System Manager (on a PC)
- a printer to log errors.

#### IC-Control Unit2 (IC-CU2)

The IC-CU2 is the control board supporting the DECT GAP-protocol and up to 7 IC-LUs located in the same cabinet. The IC-CU2 comprises 8 voice channel units (SPU as on the IC-LU) and 4 BSs interfaces. Thus a cabinet BDV 113 08 can be equipped with a maximum of 7 IC-LUs to connect up to 60 BSs.

The wiring range with remote power feeding to the BSs using only the serial communication wires SC0 and SC1 is limited to 400m. For greater line lengths additional Express Power feeding Pairs (EPP) need to be wired. The maximum wire length between BS (fed locally) and IC-CU2 or IC-LU is only data limited and may extend up to 1900 meters.

The board offers the following connections:

- the Cordless System Manager (on a PC)
- a printer to log errors
- 4 Base Stations
- the Feature Enabling Control Unit (FECU).

#### Feature Enabling Control Unit (FECU)

This plug determines which maximum number of portables are allowed to be connected to the system. This plug is available for various numbers of cordless telephones. For up to 8 portables no plug is required.

FECU no. | Number of Portables
KDU 130 05/1 | 16 *)
KDU 130 05/2 | 24 *)
KDU 130 05/3 | 32
KDU 130 05/4 | 48
KDU 130 05/5 | 64
KDU 130 05/6 | 108
KDU 130 05/7 | 210 (only with IC-CU2)

*) |  | Available for the cabinet BDV BS 101 0x .

#### IC-Line Unit (IC-LU)

The IC-LU (only for cabinet BDV 113 08) is a line board controlling and feeding up to 8 Base Stations (BS). This board transcodes the voice signal (PCM <-> ADPCM) for 8 simultaneous speech channels in the Speech Processing Unit (SPU), provides echo cancelling, controls the digital link and power feeding. The wiring distance with remote power feeding to the BSs using only the serial communication wires SC0 and SC1 is limited to 400m. For line lengths up to 1600m additional Express Power feeding Pairs (EPP) need to be wired. The maximum wire length between BS (fed locally) and IC-LU is only data limited and may extend up to 1900 meters.

In any case the total current capability of the power supply(s) has to be considered. Refer to chapter power consumption of the telephones when calculating total system power demand.

Usually the ranges mentioned above will be sufficient for most installations. For special cases where greater distances have to be covered, see System Power Consumption. Install the board in the cabinet, after the prerequisites mentioned in Placing of boards have been provided.

### Traffic Capacity Estimation Using BDV 113 08

The traffic capacity of the Cordless part of the PBX is mainly determined by the IC-CU_ and type of cabinet used and in exceptional cases also by the Base Stations. The IC-CU can handle a maximum of 56 simultaneous calls and the IC-CU2 can handle up to 60 simultaneous calls. Each Base Station has a capacity of 8 simultaneous calls.

The traffic capacity of the IC-CU_ is determined by:

- the Grade Of Service (GOS) required by the customer
- the number of speech circuits available, with a limit of 64.

The Grade Of Service is the probability that a call is rejected because of system congestion. The customer has to indicate which Grade Of Service is acceptable. A Grade Of Service of 1%, or 0.01, means an average of 1 lost call in every 100 calls.

The IC-CU2 and each IC-LU is equipped with a SPU providing 8 speech circuits that are shared by the whole cordless system. So the number of installed (up to 7) IC-LUs determine how many circuits are available to the system.

The two parameters mentioned above (GOS and the number of speech circuits) and the total amount of traffic (Erlang) that is required, are related to each other. The table below shows the capacity at a required GOS. Practically, this table is used to calculate from a given GOS and Erlang value the number of IC-LUs needed. The Erlang value is the total traffic generated by all portables. The table below shows the Erlang values for a number of speech channels and at a required GOS.

Number of IC‑LUs on Systems with | Speech circuits | Grade of service (GOS)
IC‑CU2 | IC‑CU | 2% | 1% | 0.5% | 0.1%
0 | 1 | 8 | 3.6 | 3.2 | 2.7 | 2.1
1 | 2 | 16 | 9.8 | 8.9 | 8.1 | 6.7
2 | 3 | 24 | 16.6 | 15.3 | 14.2 | 12.2
3 | 4 | 32 | 23.8 | 22.1 | 20.6 | 18.2
4 | 5 | 40 | 31 | 29 | 27.3 | 24.5
5 | 6 | 48 | 38.4 | 36.1 | 34.2 | 30.9
6 | 7 | 56 | 45.9 | 43.3 | 41.2 | 37.5
7 | – | 64 | 53.4 | 50.6 | 48.3 | 44.2

Note

64 speech channels are available but only 60 portables can simultaneously initiate calls.
Only 8 speech circuits are available on the IC-CU2 for BDV BS 101 0x.

For the calculation it is necessary to estimate the time the portables actually make calls. The table below shows the Erlang value depending on the estimated mean call-minutes for a portable telephone. These values may be different between departments depending on their activities. These values multiplied by the number of portables result in a traffic capacity that has to be provided.

Minutes per hour: | mErlang:
3 | 50
6 | 100
9 | 150
12 | 200
15 | 250
18 | 300
30 | 500
45 | 750

##### Example

A customer orders a system with 55 portable telephones, estimates that each portable generates 200 mE traffic in average. These values require a system with a traffic capacity of 11 E (0,2x55). With an accepted GOS of 0.5% the number of IC-LUs is found as follows:

The total traffic is 11 E. In the column of 0.5% GOS, the next higher value of 11 E is 14.2 E, resulting in 3 IC-LUs.

So, the system shall be equipped with 3 IC-LUs, offering the client 14.4 E instead of 11. This means that the system has an over-capacity of 3.2 E, which allows expansion of the system with 16 portables without reducing the Grade Of Service nor the need of more IC-LUs.

Thus 56 circuits with an accepted GOS of 0.5% result in a maximum traffic capacity of 41.2 E for the system.

### Traffic Capacity Estimation Using BDV BS 101 0x

The IC-CU2’s traffic capacity is limited by its 8 speech transcoders. Each Base Station has a capacity of 8 simultaneous calls. The Grade Of Service is the probability that a call is rejected because of system congestion. The customer has to indicate which Grade Of Service is acceptable to her/him. A Grade Of Service of 1%, or 0.01 means an average of 1 lost call in every 100 calls.

The GOS, the 8 speech circuits and the total amount of traffic (Erlang) that is required in the system are related to each other as shown in the table below (the Erlang value at a required GOS).

IC‑CU2 | Speech circuits | Grade of service (GOS)
2% | 1% | 0.5% | 0.1%
1 | 8 | 3.6 | 3.2 | 2.7 | 2.1

For the calculation it is necessary to estimate the time the portables actually make calls. The table below shows the Erlang value depending on the estimated mean call-minutes for a portable telephone. These values may be differ between departments depending on their activities. These values multiplied by the number of portables result in a traffic capacity that has to be provided.

##### Example

A customer orders a system with 24 portable telephones and estimates that each portable generates 150 mE in average (that is 9 minutes off-hook time per portable per hour). With an accepted GOS of 2.0% the system has a traffic capacity of 3,6 Erl. (0,15x24=3,6).

### Traffic Capacity of Base Stations

A Base Station, supports 8 speech channels, has an Erlang value of 2.7 at a GOS of 0.5%. This means that each Base Station can serve 18 portables, assuming each portable generates 150 mE during busy hour or 13.5 portables generating 200 mE each.

##### Example

A full coverage of a building shall be achieved using 4 Base Stations. We calculate that 55 portables generate 11 Erl. of traffic (e.g. 55 x 0.200 = 11 Erl). The 4 Base Stations traffic capacity is calculated by 4 x 2.7 = 10.8 Erl. This is insufficient so another Base Station in the area of the busiest part of the company has to be added.

Practically, the total capacity offered by the cordless network is generally more than sufficient, but this is from an average point of view. In certain places, traffic demands may vary such that locally the network is often blocked, or has a lower GOS than required. For instance a purchase department may easily generate 300 mE per Portable during busy hour, thus, when e.g. with 6 persons giving a very high load on the Base Station close by. It may be necessary to add a Base Station in this area to have enough capacity for others to call as well. Also think of e.g. canteens during lunch time etc.

#### More Information

Board IC-CU (ROF 157 5128) (A-Protocol)

Board IC-CU2 (ROF 157 5131/_) (GAP-Protocol)

Board IC-LU (ROF 157 5129)

Board IC-LU (ROF 157 5129)

Base Station (KRCNB 201 03/_ and KRCNB 301 03/_)

Revision: A © Ericsson Enterprise 2003