Meru Wireless Site Survey

For

A Warehouse.

Prepared by

David Steventon

28 October 2011

1. Management Summary.

Siracom were commissioned to perform a wireless site survey of a warehouse in Northampton. We were briefed ahead of the visit by the reseller. The briefing stated that good coverage is required throughout the premises for low densities of users. Coverage is particularly important in the warehouse racking area where stock is stored. These requirements were verified on site. Our key recommendations based on the briefing given are as follows:

Number of Controllers 1

Controller type MN-MC1500

Number of Access Points recommended 7

Recommended AP type MN-AP1000

Operational Channel(s) 2.4GHz #1 & 5GHz #36

The APs should be located as follows:

AP Location

1 Ground Floor - On back wall at far end of right aisle in racking area

2 Ground Floor - On 1st floor wall at end of middle aisle in racking area

3 Ground Floor - On back wall at far end of left aisle in racking area

4 Ground Floor - On 1st floor wall at centre point of open floor space

5 Ground Floor - On wall of work area adjoining Reception

6 First Floor - On rear wall in centre of office space

7 First Floor – On side wall in work area in line with central dividing wall

It is anticipated that this will provide a minimum connection speed of 62Mb/s throughout the area requested, with connection speeds of 150Mb/s across the majority of the premises as shown.

2. Background.

The end user customer has premises in XXXXXXXXXXXXXXXXXXXXXXXXXxx, Northampton. The building comprises a large ground floor divided into racked storage and functional work areas, with a Staff Room and Reception to the front. The first floor area to the front of the building has offices, a Boardroom and a further work area.

The building is a steel framework with brick and glass frontage and metal sheet outer walls to the sides and rear. The internal walls are block brick. The floor plan is shown below.

Ground Floor

First Floor

Key:

Outer & Block Walls = red line Rack storage = grey line

3. Overview of Requirement. Our briefing provided by the reseller described the requirement as follows:

To provide wireless coverage throughout the premises.

To provide good coverage to the racking area to enable stock control.

No high density usage is required. Coverage:

Areas to be covered by 2.4GHz All building

Areas to be covered by 5GHz All building

Areas where coverage is not required Plant rooms, Storage rooms, Stairwells, Bathrooms

Other areas None specified

Operational Frequencies 2.4GHz and 5GHz

Standards to be supported 802.11a,b,g,n

Resilience requirements None specified for APs or Controller

Aesthetic requirements None specified. AP1000s will be wall mounted at a height of about 2.4m in office areas and 3.5m in the open warehouse.

User Density:

Areas of very high user density (40+) None

Areas of high user density (15+) None

Performance:

Applications to be supported General applications, no voice.

Design Criteria. From the specification above we have designed to the following technical specification.

Minimum Connection Speed achievable (from test laptop)

50Mb/s

Minimum number of access points visible from any position (from test laptop).

1

Access Point locations Access points will be positioned to maximise coverage and minimise cost. An elevated position in the warehouse assists in coverage for the racking areas. A network designed for general coverage promotes location of the APs in open areas and corridors. A design for high density usage would position the APs within the identified rooms.

Design Considerations. The dynamic nature of warehousing will constantly alter the environment in which the wireless network will operate. As stock levels and content change so varying interference will be presented to the wireless system. It can therefore be assumed that dense stock levels may reduce the wireless network service and may have an adverse effect on operation. The design of the network and placement of the APs aims to minimise the effect dense stock may have and provide the coverage required for the warehouse without excessive provision. Locating an AP at alternate ends of each aisle in the racking area is considered the optimum solution towards achieving this aim.

4. Site Survey.

a. Access Point Numbers and Positions A site survey was performed with Ekahau Site Survey using the following process. From the supplied building floor plans, a desktop survey was performed to ascertain theoretical coverage using computer modelling. The desktop survey was reworked on-site to take account of the building layout detail that was not shown on the supplied plans. Using a Meru AP320 and the access point locations suggested by the desktop survey, actual signal strength and propagation was measured throughout the building. The signal strength readings obtained from walking the site showing actual coverage are contained in the appendices to this document. AP positions and numbers were amended to meet the design criteria with the minimum number of access points. The site survey suggests 7 access points deployed as follows:

Ground Floor 5 APs

First Floor 2 APs

Key:

Outer & Block Walls = red line Rack storage = grey line AP = green circle

b. Interference Analysis

Analysis of the Radio Frequency spectrum was performed using Wi-Spy and served to identify possible sources of interference and promote the most suitable channels for wireless deployment.

Non WiFi Interferers Analysis of the RF spectrum identified there were no major sources of potential interference.

Known Wi-Fi Interferers There were no other company wireless networks detected. Un-Known WiFi Interferers No significant interference was detected from surrounding wireless networks.

Non Electrical Interferers Dense stock levels may interfere with wireless service particularly if placed close to APs.

c. Channel Recommendations The levels of RF spectrum activity and potential interference detected indicate that the Meru wireless would be best allocated to Channel 1 in the 2.4 GHz operating frequency. All channels were found to be free from interference in the 5 GHz range suggesting an allocation to Channel 36.

5. Recommendations.

The site survey indicates a requirement for 7 APs to deliver the wireless network service to satisfy the requirement.

Good coverage throughout the ground floor of the premises can be achieved by 5 APs, with a minimum of 4 APs required to service the racking area. The connectivity reduces to its lowest rate of 62Mb/s at the middle end of the rack which is most central to the building. Coverage of the first floor area at the front of the building can be achieved with 2 APs. APs in the warehouse should be placed in an elevated position and at alternate ends of the aisles in the racking area. Placement of dense stock in close proximity to the APs should be avoided to best maintain wireless service.

Our key recommendations based on the briefing given are as follows:

Number of Controllers 1

Controller type MN-MC1500

Number of Access Points recommended 7

Recommended AP type MN-AP1000

Operational Channel(s) 2.4GHz #1 & 5GHz #36

The APs should be located as follows:

AP Location

1 Ground Floor - On back wall at far end of right aisle in racking area

2 Ground Floor - On 1st floor wall at end of middle aisle in racking area

3 Ground Floor - On back wall at far end of left aisle in racking area

4 Ground Floor - On 1st floor wall at centre point of open floor space

5 Ground Floor - On wall of work area adjoining Reception

6 First Floor - On rear wall in centre of office space

7 First Floor – On side wall in work area in line with central dividing wall

* Room references taken from supplied floor plan

Note. Each access point requires a network connection providing Power over Ethernet.

Health and Safety. Normal health and safety procedures should be followed during installation. The access point locations suggested in the open warehouse require access via “cherry picker” or similar. No obvious, unusual risks were detected. Siracom Liability Siracom uses industry leading tools, relevant hardware and best practice to ensure that our surveys are as accurate as possible. The environment in which wireless is deployed is inherently dynamic so our readings and extrapolations can only be estimations and we can offer no guarantees as to the ongoing accuracy of our surveys.

Appendices: RF Spectrum Analysis.

Site Survey Observed Coverage

Ground Floor

First Floor

Proposed Access Point Locations and Coverage

Ground Floor – 5 APs

First Floor - 2 APs