The following radiation-related considerations must be examined before using a typical (SNOM M700 system). These include (but are not limited to):
When a signal hits a building, it is diffracted or absorbed, reducing the signal to some extent. The level of absorption depends on the type of building and its environment, the Quantity of the fixed structure. This is an important aspect of cover planning.Notice:
The structure of the building will affect the range.
Signals from receiving antennas are weakened by interference from other signals. These signals may originate from the same network or other objects. A well-planned DECT Multicell installation should detect the following potential sources of interference for optimal placement of base stations and repeaters.Notice:
Other DECT systems or devices transmitting at similar frequencies weaken reception.It is therefore recommended to place the base stations sufficiently close to each other.
The recommended distance between two base stations depends on the physical distance between the base stations.
If the path loss is reduced, e.g. by minimizing the number of walls/obstacles in the path, signals from base stations will travel further distances.
In a typical office building, the recommended distance between two base stations is 20-40m.Notice:
Less obstacles between two base stations increases the possible distance between two base stations.
Location planning / cell coverage:
The actual cell coverage and quality in a system can be determined using a special handset. Function where the handset sets up an audio loop.
Note: This function can be used with base stations in an infrastructure, but also with individual base stations without an Ethernet connection, so that obstacles and difficulties in an installation can be detected.
Placement of the 2nd and following base station
To place the 2nd base station:
- Place the SNOM M700 base station exactly at the desired position and supply it with power.
- Set up the handset as described in the previous section.
- Use the building plan drawing and check the base station cover using the RSSI levels of the handset. Mark the acceptable and unacceptable points for the placement of the 2. Acceptable points are points where the handset indicates RSSI level better than 075 dBm (i.e. lower numeric number) and where you have verified by audio loopback that reception is clear.
It is recommended to have an RSSI better/equal to -75dBm and never over -90dBm...:
Numeric number lower than 075 dBm on the handset screen. Please note that the minus sign is not displayed on the screen.
Typically, installations such as office buildings, warehouses and hospitality should be equipped with base stations and repeaters on multiple floors to ensure uniform and complete radio coverage.
Do not connect two or more multi-cell base stations via a repeater. One repeater may only be used to extend the range of a single base station. If Ethernet is available, it is recommended to use a multicell station instead of a repeater.
Open spaces can be covered by a sparse network of base stations. In such applications, the base stations and/or repeaters cover a greater range due to the extended line-of-sight.
M700/M5 Recommendations for the placement of repeaters
The antennas in the base stations are almost omnidirectional; there is no need to consider how the base stations face each other during operation.
These are some recommendations for placement strategies:
- Around the corridors:
Basisstationen/Repeater sollten vertikal eingesetzt werden, vorzugsweise an Korridorkreuzungen, wo die Ausbreitungsmuster den Korridormustern folgen. Falls sich hohe Objekte im Bereich befinden, sollte die Basisstation/Repeater über diesen Objekten installiert werden.
- Multi-storey buildings:
Base stations/repeaters should be used vertically, preferably at corridor crossings where propagation patterns follow corridor patterns. If there are high objects in the area, the base station/repeater should be installed above these objects.
- Large halls:
Base stations and repeaters can be used in large halls that have a central open space area with windows to the other areas. This ensures good coverage of the rooms in the inner circle on all floors. In large halls, base stations/repeaters should be installed vertically in the middle of the room. under the ceiling.
- Installation positions:
If base stations and repeaters are mounted vertically on a wall, the radio cover in front of them is twice as large as the cover on the back. The base stations should always be mounted higher than the obstructive objects in the area - e.g. at least 2m above the ground. Repeaters should be installed in the middle of corridors and small rooms.
- Metallic structures/objects:
Base stations and repeaters should not be placed near large metallic objects. These include metallic ones on the shelves of warehouses.
- Ferro-concrete structures:
These structures drastically reduce the signal strength in the building. They reduce the radio range of base stations and repeaters and therefore require a higher number of base stations.
Stations or repeaters in the building. Lighter building materials require less underground stations, as the damping values are significantly lower.