Cisco IP DECT 6800 Series Deployment Guide€¦ · The software associated with the hardware for this document are: • DBS-210 470 B6 • CP-6825 470 B3 The Single cell system is

Date printed: 3/23/2020 Cisco IP DECT 6800 Series Deployment Guide

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Cisco IP DECT 6800 Series

Deployment Guide

Installation Guide to plan and install Cisco IP DECT 6800 Systems




Table of Contents 1 Introduction ................................................................................................................................ 3

2 Purpose ....................................................................................................................................... 4

Scope .......................................................................................................................................... 4

Equipment .................................................................................................................................. 4

3 Standard Deployment Models .................................................................................................... 4

Single Cell System: .................................................................................................................... 4 Multi Cell System: ...................................................................................................................... 4

4 Capacity Planning: ..................................................................................................................... 4

Density Considerations ............................................................................................................... 5 Audio Codec Considerations .................................................................................................... 5

Channel Capacity Planning Table: ........................................................................................... 6

5 Deployment Considerations ....................................................................................................... 6

Radio Considerations ................................................................................................................. 6 Site Survey ................................................................................................................................. 8

Site Survey Tool ....................................................................................................................... 8

6 Single Cell and Multi Cell installation ..................................................................................... 10

Single Cell Installation ............................................................................................................. 10

Determining Install Location for a Base Station .................................................................... 10 Multi Cell Planning .................................................................................................................. 11

Installing a Base station ............................................................................................................ 12 Caveats ................................................................................................................................... 12

Scenario 1: Conference Room ............................................................................................... 13 Scenario 2: Multistory Shops ................................................................................................. 13

Scenario 3: Mall Store or Small Shop .................................................................................... 14

7 Network Considerations ........................................................................................................... 15

8 Additional Documentation ....................................................................................................... 15




Cisco IP DECT 6800 Series consists of Cisco IPDECT DBS-210 Multi-cell base station and Cisco IP

DECT Phone 6825 handset, is built on Digital Enhanced Cordless Telecommunications (DECT)

technology, to provide the ease of cordless capabilities and follows open SIP protocol to provide a voice

over IP solution. The DECT base station connects with the internet over Ethernet to the call server and

provisioning servers. DECT base station uses DECT protocol to connect with the handset.

DECT frequency is in the unlicensed residential spectrum and thus it may interfere with commonly-used

residential and commercial appliances. DECT is developed for short distance communication and a large

number of users, which is useful for home cordless phones and small to medium size installs.

DECT works close to the 1.9 GHz frequency band to avoid interference with Bluetooth, Wi-Fi, and

microwave frequencies. The actual DECT frequency used is regulated by individual countries.

Like other radio technologies, DECT uses a combination of Frequency Division Multiplexing (channels),

and Time Division Multiplexing (time slots) techniques. DECT devices share available channels on the

radio spectrum and limits the active number of devices when in close range of each other.

DECT as a wireless protocol designed for high subscriber density with a lower bit rate that provides good

voice quality at 32kbps per channel.

Add additional base stations and connect them into a multicell system to extend the coverage range.

Figure 2: IP DECT Phone 6825

Figure 1: IP DECT DBS-210 Multi-cell Base Station




This document describes the best practices for installing a Single Cell system and Multi Cell system with

the Cisco IP DECT 6800 Series with Multiplatform Firmware handsets and base station. It includes where

to mount the base station to ensure the best DECT handset coverage.

The DECT equipment used in the examples is:

• Cisco IP DECT 210 Multi-cell Base Station

Cisco IP DECT 6825 Handset

The software associated with the hardware for this document are:

• DBS-210 470 B6

• CP-6825 470 B3

The Single cell system is one base station that works independently, even if there are other base stations

on the same LAN (local area network). All configuration parameters are sent to and stored on the base

station. The handsets registered to this base station may not roam to other base stations.

The Multicell System has a group of base stations on a LAN that have the same Multi-cell Chain ID. All

the base stations using the same Multi-cell Chain ID will use the same data by synchronizing.

Each handset uses DECT channels on the base station. If you have too many handsets for a base

station, not all handsets can place calls. Thus, it is necessary to plan the capacity, first. Capacity for

each installation includes the number of simultaneous users, and projected number of simultaneous calls.

Capacity planning requires the following knowledge for each site:

• Intended number of handsets simultaneously registered

• Intended traffic load

• Intended coverage area




Use these conditions when you consider the density and possible interference:

• Low Density, Low Interference: One Cisco IP DECT DBS-210 provides a coverage of 300

meters in a straight line without radio interference. This means, if the density is less than 5

simultaneous calls and not more than 30 simultaneous registrations, you only need one Cisco

IP DECT DBS-210.

• Low Density, High Interference: One Cisco IP DECT DBS-210 base station can handle up

to 30 registrations of handsets for up to 10 narrowband calls or 5 wideband calls. If you add

another base station, you can register 60 handsets, and support 16 narrowband or 8 wideband

calls at one time. If high interference is expected due to RF attenuation or RF interferences,

you can add more base stations.

• High Density, Less Interference: One Cisco IP DECT DBS-210 provides coverage of 20-

50 meters indoors depending on the interference and attenuation. It gives 300 meters

coverage in plain outdoors. The 300 meters coverage area is also valid for a room that is 300

meters in radius without any interference and attenuations.

• High Density, High Interference: You need multiple base stations to get the required

capacity. In high density areas where you need maximum channels, base stations placed too

close together can cause interference. To minimize base station interference, follow these

recommendations to get a better audio experience for end users.

In high density areas where you need maximum channels, base stations placed too close together can

cause interference. To minimize base station interference, follow these recommendations to get a better

audio experience for end users.

• Install base stations at least 2 meters away from each other.

• In the 20 MHz frequency spectrum (EU spectrum), the density should be 7 base stations or less in

100 square meters.

• In the 10 MHz frequency spectrum (Americas spectrum), the density should be 4 base stations or

less in 100 square meters.

Audio Codec Considerations You need to consider the audio codecs you will use during capacity planning.

• The Cisco IP DECT 6825 handsets support G722 for wideband and G726 for narrow band.

• The Cisco IP DECT DBS-210 base station supports G.711 a-law & u-law, G.722.2, G.726

and G.729a/ab

The Base station does the required transcoding based on the negotiated codec for each call.

The Wideband codec occupies 2 channels, while the narrowband codec occupies 1 channel.

If you expect more simultaneous calls, use the narrowband to increase the available number of channels.

If you configure wideband, you may need to add more base stations to increase the channel capacity




Channel Capacity Planning Table: Channel capacity table provides the guidelines for the number of registered handsets and number of

simultaneous calls supported. First row is for a Single Cell system.

Number of DBS-210

in the Network

Maximum Number of

Registrations

Maximum Number of

Concurrent

Wideband Calls*

Maximum Number of

Concurrent

Narrowband Calls*

1 30 5 10

2 60 8 16

3 90 12 24

4 120 16 32

5 150 20 40

6 180 24 48

7 210 28 56

8 240 32 64

9 270 36 72

10 300 40 80

20 600 80 160

50 1000 200 400

100 1000 400 800

200 1000 800 1000

254 1000 1000 1000

DECT is resilient to interference with wireless frequencies commonly used for cell phones, Wi-Fi radios,

and Bluetooth headsets. If there is interference detected, the DECT protocol adapts the channel to

minimize the impact. To ensure optimum use of the handsets, perform a site survey and mount the base

station in a strategic location for the best handset coverage.

For best handset coverage, planning should consider the effects of coverage by RF attenuation and RF

interference.

Before planning the installation, the site survey should try to identify possible radio frequency attenuation

objects in the coverage area. This section provides a few common attenuation and interference objects in

a typical install site.

Building Penetration:

When a signal strikes a wall, it is diffracted or absorbed. This may cause the signal to be reduced or

distorted. The amount of absorption is dependent on the building type and its environment and the amount

* Assumes there are no other active calls




of solid structure which includes concrete, metal frames, metallic doors, thickness and so on. This is an

important consideration when you plan the coverage.

Interference Sources:

The interference from other signals or from the same network can make the received signals weaker.

Some network interference is handled by DECT and it uses different channels, if there are channels

available. For interference from other signals, identify and plan the location of the base station. Typical

sources of interference in a typical site are as follows:

• Microwave oven

• Ovens

• HVAC

Note: DECT is not affected by Bluetooth, Wi-Fi, and wireless cellular networks. The DECT frequencies

are different from the frequencies used in for these technologies.

Radio/Cell Range:

The ideal situation is to have the base station and handset in line-of-sight at all times. Line of sight means

the straight physical path between the base station and the handset. Any interference or RF attenuation

Figure 8: RF Diffraction and Multiple Path

Figure 9: RF Attenuation effect on Coverage Area




materials in the line of sight reduces the coverage distance. Every RF attenuation material has unique

attenuation characteristic. The diagram above explains the effect of RF attenuation material to the

coverage area.

Attenuation

The table in this section provides the attenuation levels for each material. The thickness of the material

also plays a significant role in the attenuation. If the material is thicker, the attenuation is higher. In the

table below:

• If the wood material is thick, the attenuation level may change from low to medium.

• If the glass door is very thick, the attenuation level may change from medium to high.

• If there are tiles on both sides of the walls, attenuation is almost doubled through the wall

Material Level of Attenuation Comments

Wood Low Doors, floors, and so on

Plastics Low Room partitions

Tinted Glass Medium Wall hangings, glass door, and window

Living Objects Medium Crowds, and Plants

Bricks Medium Walls

Ceramic High Tiles

Concrete High Walls, pillars, floors, and stairs

Metal Very High Elevator, and cabinet

We recommend that you identify the medium and high attenuation materials in your coverage

plan.

Every installation site is different, even if the site is one in a group of retail or restaurant locations built

with the same plan. Always create a site map to identify the best location to mount the base station at each

site.

The site map must identify the RF attenuation materials and RF interference sources as described in the

previous sections. The Site Survey tool (below) helps to identify the actual coverage received as Radio

Signal Strength Indication (RSSI).

One base station can provide an indoor coverage radius of less than 50 m (164 feet), depending on the site

map and the attenuation characteristics of the materials in the line of sight.

The DECT base station must be placed in the center of the active work area in the building with a line of

sight to all the coverage area.

Site Survey Tool Preparing for the survey:

1. Power on the DBS-210 base station and wait until you see Green LED light at the top of the base

station.

2. Power on the 6825 handsets. Make sure battery is fully charged before entering site survey.




3. Put the Cisco IP DECT 6825 handset into Site Survey mode.

Figure 3: The Cisco DECT Phone 6825

Preparing for the survey:

1. Press menu.

2. Press *47*.

3. Press the Select button to select the base station

• If more than one base station is listed, find the desired station by matching its MAC address.

The handset displays the signal strength from the base station

Figure 4: IP Search Screen

Select button Menu button

Keypad




4. Move around the building to confirm the coverage area of this base station.

• The handset autocratically updates the signal strength to the base stations shown with a

green check mark, orange triangle, or red circle. The update may take a few seconds to

synchronize with the base station

If there is no connection, the base station doesn’t appear on the list.

Figure 5: Good Figure 6: Average Figure 7: Poor

The following describes the items listed in the IP Search screen.

MAC MAC of the base station If multiple base stations are seen, this identifies the base station.

IP IP address of the base station

RFPI Radio Fixed Part Identity

RSSI Received Signal Strength Indicator Indicates the received signal strength in decibel-milliwatt.

The following describes the RSSI Value

RSSI Value Indication of Quality

Greater than -50 dBm Excellent

-50 dBm Up to -70 dBm Very Good

-70 dBm Up to -80 dBm Just Enough

Less than -80 dBm Poor

In the area of “Just Enough” quality of RSSI, we recommend that you add more base station or move the

existing base station to check if it covers the desired covered area.

Capacity planning helps to identify if a Single cell or a Multicell system is required. We recommend a

Single cell set up for small area with low density, otherwise you can set up a Multi cell system.

Typically, a small retail store (for example in a mall) needs a single cell system. But you should confirm

this with a site survey.

This section guides you in the physical placement of the base station in a single cell system.

To optimize the time in the installation process, mount the base station using these recommendations:




• Small to Medium Size Area: For an ordinary store in a shopping mall, the. base station

must be installed vertically in the middle of the space below the false ceiling.

• Two-floor buildings: Mount the base station at the center of the first-floor’s false ceiling.

• Large Halls: These are typically large retail stores with more than 100 square meters (1100

square feet). The base station should be installed vertically in the middle of the space below

the false ceiling.

Follow these steps to fine-tune the location:

1. Place the base station in the center with line of sight to the coverage area.

2. Start the site survey tool. For more information, see Site Survey Tool.

3. Move around the entire coverage area and locate any dead spots.

If there are any dead spots, move the base station towards the dead spots and repeat the site

survey until they are covered.

4. When you find a place where there are no dead spots, mount the base station in the selected

location.

Coverage for a multicell system should provide an overlap of at least 20% to make sure that a handset

can roam freely from one base station to another with no loss of coverage.

We recommend that you place the base stations like the following figure to maximize the coverage. The

overlap doesn't have to be exact. The placement depends on the RF attenuation in the deployment site.

Based on the environment, you may have to place base stations closely. In the figure, it is assumed that

there is no RF loss due to the environment.

Figure 8: Multicell Overlap

Good

Weak

Poor

Good

Weak

Poor

20%




For Single cell and Multicell installation, this section provides the best practices for the direction and

placement of the base station in the selected location.

The antennas are omnidirectional. Follow these recommendations for optimal signal coverage:

• Place the base station in the center of the desired coverage area for optimal coverage.

• Place the base station at least 2 m (6.5’) above the floor, so that line of sight is maximized

for all of the desired coverage area.

• Don’t install the base station on a metal rack; coverage is reduced by the metal

• Don’t install the base station at the end of the room unless the desired coverage area is at that

end only

• Don’t install a base station in the basement floor or on a table in the basement and expect it

to provide coverage to the first floor

• Don’t install a base station behind a metal door (including an elevator) if the coverage area is

on the other side of door

• Don’t place the base station near high attenuation materials, such as, metal and concrete,

because this reduces the RSSI value as displayed on the handset

Figure 9: Multicell Parallel Overlap




• Don’t place the base station inside electrical boxes, or closets. The base station must be

clearly visible in the working area. Use the ceiling mounting kits if the space is limited on

the walls or flat surfaces

The following sections are the example scenarios to consider around density during the capacity planning.

• You have a conference room that holds 50 people. You expect each person to have a handset

and you expect there will be a maximum of 20 simultaneous calls. You will need:

o 5 base stations if the calls use wideband

o 3 base stations if the calls use.

• Install the base station in the false ceiling.

For a medium-sized, two-floor shop with about 10 employees and about 5 simultaneous calls, the capacity

table suggests you need only one base station. But with two floors. one base station isn't enough because

of RF attenuation. We recommend at least one base station per floor. If there is an elevator to move

between floors, you might need one or more base stations near the elevator to provide better coverage

when you move between the floors.

Install the base station in the false ceiling of each of the base floor.

Presenter area

Figure 10: Conference Room




If you have a typical mall store or small shop, one base station is likely enough. But it should be installed

in the center of the store to ensure good coverage.

Figure 7: Sample Location – Small Store

If the store has a metal door between the service side and the main area,

select one of the options for good coverage:

- add one or more base stations

- install the base station close to the metal door.

Install the base station at least 2 m above the floor, in the center of the building.

The scenarios are for illustrative purposes only. We recommend that you perform a site survey

using the site survey tool to make sure that there are dead spots in the coverage.

Figure 11: Multistory shops




• Switch ports must be opened for base station to connect and get an IP address.

• If planning to use a Voice VLAN, make sure that the Voice VLAN is configured for the

correct switch ports.

• If planning to use PoE for the base station, make sure that the switch is appropriately

configured and that there is enough power to allocate IEEE Class 2 PoE for the base station.

• IP address allocation for the base station can be done through, either DHCP or a Static IP

address. After the IP address is assigned, it appears on the site survey tool.

• The switch must open (S)NTP, DNS, HTTP(S), SIP(S) and (S)RTP ports for the device to

work properly. Contact your Service Provider to know the exact port numbers that you need

to open for each of the protocol.

• If LDAP is used for directories, make sure to open the LDAP ports.

If DHCP options are used to point to the provisioning server, they must be configured

Make sure that the HTTP(S) port is opened for connections initiated by base station. This is

required for Firmware upgrades, provisioning, and to push the logs.

More Cisco IP DECT 6800 Series documents are available from

https://www.cisco.com/c/en/us/support/collaboration-endpoints/ip-dect-6800-series-multiplatform-

firmware/tsd-products-support-series-home.html

https://www.cisco.com/c/en/us/support/collaboration-endpoints/ip-dect-6800-series-multiplatform-firmware/tsd-products-support-series-home.html

https://www.cisco.com/c/en/us/support/collaboration-endpoints/ip-dect-6800-series-multiplatform-firmware/tsd-products-support-series-home.html

Documents

Cisco IP DECT 6800 Series Deployment Guide€¦ · The software associated with the hardware for this document are: • DBS-210 470 B6 • CP-6825 470 B3 The Single cell system is