CSE5 ITP High Density Wireless Design REPORT

CSE5 ITP High Density Wireless Design

Undercroft Lecture Theatre – La Trobe University

Project QSS

Qaiser Tanveer : 17650920 Sai Shyam Tekumalla : 18046988 Sai Eshwar Chellapuram : 18047717

Table of Contents

1 Overview..............................................................................................................................3

2 Project Objective/Requirement..........................................................................................3

3 Project Benefits...................................................................................................................4

4 Challenges/ Current Situation............................................................................................4

5 Analysis of solution and recommendation.......................................................................5

6 Hardware and Software components................................................................................6

7 Risk Analysis.......................................................................................................................6

8 Stakeholder Analysis..........................................................................................................7

9 Existing Network Design...................................................................................................8

10 Site Survey.........................................................................................................................11

11 Estimating Client and AP Counts....................................................................................20

12 Estimating the Access Point Association Limit.............................................................22

13 Estimating Clients per AP Capacity................................................................................25

14 Estimating additional APs................................................................................................26

15 Proposed Solution.............................................................................................................27

16 Channel Selection..............................................................................................................28

17 AP Mounting Points..........................................................................................................29

18 AP installation...................................................................................................................30

19 Budget Estimation and Financial Analysis....................................................................30

20 Project Implementation....................................................................................................32

21 Schedule Estimation and Work Breakdown Structure..................................................36

22 Communication Plan.........................................................................................................37

23 Bibliography......................................................................................................................39

1 Overview

This report provides an analysis of La Trobe University’s network to develop a new

indoor wireless network using the existing network design and adding some new and updated

hardware components so that the network can sustain to its optimum level in next 4 years.

Due to increasing number of student logins each day, management wants to facilitate

students with a good network access and in every area of the floor. Also they want to provide

a strong network system which is harmonious in supporting heavy loads during the peak

hours, have multiple login facilities for each user and eliminate black spots at the same time.

Therefore, this project is to upgrade a wireless hardware such as wireless controller and

adding access points throughout the building, so that each student/staff can have suitable

network access without interference and with promised speed limits as per university policy.

We have chosen to do the network design for the undercroft lecture theatre area next to

the David Myer’s bus stop area, directly underneath the middle of the David Myer building

next to a large open space with stained-glass windows.

2 Project Objective/Requirement

To provide RF design for location specific parameters applicable to wireless design.

To design a wireless network catering 20 active devices on an average in a wireless

cell (allowing 25% HD Video call, 50% web browsing).

Real time audio/video (MS Lync, Skype, FaceTime and other multimedia) to be

supported over wireless network.

Streaming video (Netflix, YouTube) to be given priority to in the wireless network

To provide power planning (of APs) according to different client types used.

To provide the facility with increased network capacity.

To provide a design with future expansion capabilities.

Identify and rectify different points of failure in the existing network.

Improve existing network security, redundancy, fault tolerance perspectives to

increase overall efficiency of the network.

3 Project Benefits

Analysing different acute points of failure and providing a redundant solution will

help the network to be fault tolerant. This will help save a great amount of money and

provide network stability lacking which results in network failure and overall kiosk.

Implementation of the network design with proposed hardware upgrades will facilitate

network with the incremental expansion with the growing demands.

Improving network speed and capacity will facilitate the users and guest with the easy

access and suitable bandwidth around the day, irrespective of the peak hours and off

peak hour’s usage. This will help provide a suitable distribution of the network usage

across the access points and also discriminate overloading problems of the network

devices.

4 Challenges/ Current Situation

RF radio signals are susceptible to obstructions where interference can reduce the throughput

and signal strength of the device. We have ensured the following obstructions were the main

factors that were probably degrading the signal performance of the surrounding areas of the

undercroft area. This is the reason the area has weak wireless signal strength caused by

bleeding as AP‘s are not overlapping creating connection disruptions and discontinuous

signal coverage and thus denying sufficient access for the users.

One of the most challenging factors in the network design of Undercroft building is the

architectural design of the building. The major concern in the installation of the new AP’s

around the facility is the complex roof structure, which limits with only few possible points

where new AP’s can be installed for example if we look into the architectural design of the

Undercroft Lecture theatre and the common space the structure of ceiling doesn’t help to

mount the any access points on the ceiling, However in the proposed design will overcome

this issue by mounting the access points on side walls rather than on the roof of the lounge.

Cannot mount an Access point at this position It affects the signal strength and the equality of the overall signal. The Sides of the Lecture are the places where the access points can be mounted.

5 Analysis of solution and recommendation

As per the client’s specifications, requirements, cost and time constraints, we suggest

to that the implementing a proposed design in the undercroft area and making

necessary changes by adding required hardware and network resources to increase

efficiency, throughput, network performance and reliability. This solution will meet

the client requirement to meet the end user requirements of the network usage.

In this new design, we propose to implement a high performance hardware such as

switches, access points and other dedicated devices which will aid to increase the

network performance, scalability and availability of network across the undercroft

area.

In addition, we will also increase the numbers of access points across the building to

get a better coverage, signal strength and throughput.

The new design will be proficient enough to withstand the ever growing demands of

the wireless network.

Since our novel and first-hand design is embedded with all new technology, access

points and switches, any changes to the technology in the near future would not have

much impression on the hardware and the hardware will be well-suited enough to

embrace the future technologies without many changes.

6 Hardware and Software components

Hardware Components: All Cisco devices were used

Antennas

Access Points

Cables

Software:

Ekahau Site Survey tool – Heat Mapper

Visiwave Site Survey tool

Google Maps

OPNET simulation tool

7 Risk Analysis

High Risk: SECURITY

The security is one of the most significant concerns in any wireless network design.

Therefore, in our design we will consider all the security aspects to meet the La Trobe

university standards and polices to provide a secured wireless network.

For example in the access layer all switch ports need to be configured with security

configuration to control which devices will be allowed to connect to the network.

Moreover, in the distribution layer, to control the traffic flow, security policies needs

to be implemented.

Physical Security: It is one of the major concerns for the network design. In the access

layer, the devices needs to be secured from being stolen or damaged by trespassers.

The best solution for this is to mount the access point in a safe and secure place where

no one can reach or access them except the technician.

Medium Risk: SIGNAL INTERFERENCE AND WIRELESS COVERAGE

There are some sources in the Undercroft Lecture Theatre that may cause signal

interference such as card access near the entrance of the lecture theatre, the lecture theatre

architecture and 4 vending machine just outside the Lecture Theatre near the bus stop.

By Using site survey tools and software’s such as “VisiWave” and “Ekahau Heat

Mapper” will help us to test the strength of wireless signals to detect which area has less

wireless coverage.

Therefore, we will minimize the risk of this interference and signal coverage by allocating

access points in proper locations away from those sources.

8 Stakeholder Analysis

Users (Students, Staffs, Guests)

Gareth D’SouzaSenior Network Security Specialist

Qaiser – Project ManagerSai Shyam – Network SpecialistSai Eshwar – Network Designer

Rasika Nayanajith Network Team Leader

STAKEHOLDERS

9 Existing Network Design

RF radio signals are susceptible to obstructions where interference can reduce the throughput

and signal strength of the device. We have ensured the following obstructions were the main

factors that were probably degrading the signal performance of the surrounding areas of DM

building. This is the reason the area has weak wireless signal strength caused by bleeding as

AP‘s are not overlapping creating connection disruptions for the users and denying to access

the HD apps.

The area near the bus stop

Metal obstructions such as heating and air-conditioning ducts, myki vending machine,

beverage & chocolate vending machines and superstructures constructed of drywall /wood

block walls; power cabling could be the main causes of interference in this area.

The lawn area near the bus stop

The wide lawn area near the bus stop has the largest bleeding area as the signal coverage of

the access points in this area is not overlapping each other.

Though the two sides of the back lawn are enclosed by PE, HUED & DMW, unfortunately

the signal strength is very weak at that area.

SSID “LTU Guest” just like “eduroam” has some problems with the coverage and signal

strength. The yellow and red patches confirm that the areas need a little more help with

additional AP’s in that area as that area lacks a good signal strength and it can be confirmed

form the elaborate survey that was performed.

The architecture of the building is of the major concern in design, as the fancy interior of the

building leaves with a very few places where new access points can be installed. Although

some areas in the building have already been installed with the connecting ports for new AP’s

that can be efficiently used.

Access Point at Undercroft Lecture Theatre

The blue box highlighted in the floor plan indicates the position of access points in the

Undercroft area. There are no access points inside the lecture theatre as such. The access

points are right outside the lecture theatre as shown in the figure. The capacity of the lecture

theatre is 189.

10 Site Survey

The survey was performed in the undercroft lecture theatre. As you can see from the above

statistics that the access points work in both 2.4GHz and 5GHz range, but the maximum

percentage of devices work in 2.4GHz range and only 19.8% work in 5GHz range. Also the

channels seen here are majorly in ch#6, #1 and #36. Security modes are managed almost

equally in clear and WPA2 mode.

2.4GHz and 5GHz

The 5 GHz Frequency Band Offers Greater Capacity than the 2.4 GHz Band. Significant

differences in the amount of available unlicensed spectrum between the 2.4 GHz ISM band

and the 5 GHz UNII bands influences network design. The 2.4 GHz ISM band is comprised

of only three non-overlapping 20 MHz channels that can be used for Wi-Fi networks.

Due to the relatively sparse amount of spectrum available in the 2.4 GHz band, there are

typically not enough channels for multiple co-located AP’s to serve a high-density client

population without negatively affecting the non-overlapping channel reuse plan and

introducing significant levels of co-channel interference. Therefore, in a high-density network

design, only a single 2.4 GHz AP radio should provide service within a physical coverage

area. Minimizing Co-Channel Interference (CCI) between adjacent 2.4 GHz cells is a primary

high-density WLAN design consideration, yet even with sound design practices, it is often

not possible to completely eliminate CCI in the 2.4 GHz frequency band due to inadequate

spectral capacity.

The 5 GHz bands comprises four unique frequency bands and a total of 23 non-overlapping

20-MHz channels. In contrast to the 2.4 GHz ISM band, the 5 GHz bands offer much more

spectral capacity for Wi-Fi networks. This facilitates greater separation between access points

operating on the same channel and allows for a better frequency reuse plan. In high-density

environments, multiple 5 GHz AP radios can be physically co-located, using different

channels, in order to increase capacity. These factors make 5 GHz operation essential for

successful high-density Wi-Fi network deployments.

#SSID: eduroam

The above statistics is from the survey results. As you can see, it is a list of access points

under the SSID eduroam, working both in 2.4GHz and 5GHz range. It is not the entire list of

access points, only a few, it covers the main idea behind our theory and the inference needed

to work on the high density design. Site survey was performed keeping in mind the future

network. The device used to capture the results was the latest surface tab, so it was able to

capture the statistics for 802.11ac mode. Similarly the results were captured AP’s working in

every other SSIDs.

SSID User Group

Eduroam Teaching purposes for staffs and students

LTUWireless2 Staffs and students

LTUGuest Public internet users and guests

NewToLTU Internet technical management

Users connect via distinct SSIDs for each user segment, with each SSID being segregated to

its own respective VLAN. This wireless connection is secured by respective wireless

authentication protocols. Above table provides an example of SSIDs that are used in

universities. The number of SSIDs should be kept to a minimum to avoid a negative

performance impact because of excessive management traffic. Each SSID requires a separate

beacon message that will be broadcast at the lowest mandatory data rate and can significantly

impact the performance in a high density design.

Undercroft Lecture Theatre: Signal Strength Map

This map shows the entire survey area. The data collected is also shown using colored lines

and dots. The colors indicate the signal strength of the access points at each location. In this

case, the color is based on the signal strength of the associated AP. This heat map shows the

signal strength in the Undercroft Lecture Theatre. The green area represents the strongest

signal, followed by the yellow areas, with the reddish areas representing the weakest signal.

Within each color, different shades of the base color show different signal levels within that

color. The legend is across the top of the map. In this case, the units are dBm since signal

strengths are being mapped. There are some spots that has no signal at all, the white patches

in the heat map are the bleeding areas.

Undercroft Lecture Theatre: Survey Map

The above map shows the entire survey area. The data collected is also shown using colored

lines and dots. The above site survey result depicts the AP coverage across the Undercroft

lecture theatre. It shows the overlapping of channels with a minimum SNR of 18db. This

includes results for all the access points with all SSID’s (eduroam, NewToLTU,

LTUWireless2, LTUGuest). The white spot in the survey are the places with no coverage and

are considered to be the bleeding spots.

Undercroft AP Coverage Area

The above result shows the overlapping AP coverages highlighted, with minimum signal-to-

noise ratio being 18dB. The results were obtained for all the SSIDs. The spots in white colour

are the ones that has no coverage. These areas are said to be the bleeding zones.

Undercroft Lecture Theatre: Data Value Chart

With a value chart, you can see the actual data values collected and where they were located.

The survey area is split into cells. Each cell shows counts and averages of data points

collected within that cell. In this case, the number of data points in each cell is shown along

with the average signal strength, channels, SNR and noise values for all readings from AP’s.

The spectrum average is 2.4GHz and the maximum spectrum is 5GHz across all the SSID’s

(eduroam, LTUWireless2, NewToLTU, LTUGuest). The value chart above is a bit cluttered,

the below figure shows the values of average signal strength, SNR, noise values, channels

and data rates from all the AP’s in one particular region.

From the above value chart, we can infer that, the signal strength at the top left corner is -83.6

dBm, this means the signal strength is poor. The channels seen support both 2.4GHz and

5GHz range. Noise level is high in all the four cells. The data rate seen at the bottom right

corner is around -69.3 dBm, this is during peak hour and the signal strength does not seem to

be great. These areas are the largest bleeding areas as the signal strength is close to none and

it could also mean that the APs in this areas are non-overlapping. Noise levels are pretty high

when compared to the accepted levels and that is one major factor affecting the data rates,

throughput and the signal strength of that area for all SSID’s.

A “capacity-oriented” design introduces a significant differential between the distance at

which clients will associate to an AP (association range > -67 dBm) and the distance at which

the AP signal can create co-channel interference with other APs operating on the same

channel (contention range -67 to -85 dBm). Therefore, APs will cause co-channel

interference at much farther distances than the clients will typically associate to the APs. Co-

channel interference is more aptly referred to as medium contention between Wi-Fi stations

because they are able to de-modulate the frame preamble from one another and defer

concurrent transmission to prevent frame corruption. Co-channel interference is typically the

most significant cause of limited performance and capacity in a Wi-Fi network.

This effectively reduces the Wi-Fi cell size at which clients should be associated to individual

APs. As clients move farther from the AP and signal strength declines toward the -67 dBm

threshold, they should be able to discover and roam to an alternate AP that can continue to

provide a sufficiently high-strength signal. This requires that network administrators design

the Wi-Fi network so that AP coverage areas provide overlap at or above -67 dBm. When

compared to a “coverage-oriented” network, designed to provide signal in all locations at

much lower levels (- 72 dBm for example), this effectively reduces cell sizing and distance

between APs. Access points will be located in closer proximity to one another in “capacity-

oriented” Wi-Fi networks.

Coverage Vs Capacity

We can increase the use of 5 GHz RF spectrum for less interference and more channels

(capacity). Shrinking AP cell sizes as much as possible. Increase the AP count, but only to

the extent of estimated capacity (more is not better). Understand required Capacity to avoid

over--building network (increases interference unnecessarily). High frequency re-use. Use of

directional antennas.

11 Estimating Client and AP Counts

This is the most common question asked about Wi-Fi. The answer changes dramatically

depending on:

Key performance metrics (applications, bandwidth, latency)

Client capability

Estimated number of devices per AP

Physical density of people

AP hardware selection

Whether encryption will be utilized and what type

Estimating the Number of Client Devices

While it is obvious that all 189 attendees at the Undercroft Lecture Theatre will not use the

network simultaneously, we still need to determine some reasonable number for network

sizing. The state of a Wi-Fi device becomes an important factor i.e. if it is active and

transmitting or associated but idle. Correctly scaling capacity needs to consider both the

number of clients that might be connected as well as the number actually using the network.

There should always be enough APs such that any random client can associate at any time

and transmit data from any part of the coverage area.

Lecture Theatre Example:

The chance of all 189 attendees bringing a Wi-Fi device, connecting it and transmitting at the

same time is almost nil; but there is no easy way to determine what number is likely. This is

further complicated by the assumption the number of devices will increase over time. One

way to estimate this number makes the following assumptions:

The maximum number of Wi-Fi devices associated but idle on the network will

always be lesser than the number that are active

Attendees will typically use up to a maximum of 4 wireless device at a time

Not all attendees will bring Wi-Fi devices or connect them to the network - estimate

1%

Unless otherwise indicated, more than 99% of these devices are connected to the

network at a single point of time

Unless otherwise indicated, more than 99% of all devices that are connected to Wi-Fi

are active at the same time

Assumptions Percentage of Uptake Number of Clients

Maximum capacity 100% 189

Users bringing a Wi-Fi

device

99% 187 (Appx.)

Devices connected to the

WLAN

>99% 748.44 ~ 750

Active devices >99% 750

The percentages offered here represent a place to start. The existing wireless network should

be taken into account as it may have valuable information about the current number of active

devices. The percentages should be adjusted accordingly. There are several factors used to

determine AP counts; • Association limit • Capacity limit • Coverage limit

12 Estimating the Access Point Association Limit

Assuming that Cisco APs currently support a maximum of 50 clients per AP. Therefore, the

total number of APs needed to ensure all the Wi-Fi devices can get service if desired is

calculated as follows:

Maximum number of Wi-Fi devices/ 50 associations per AP

Identifying client device capabilities

Identify the client device types that will be supported within the environment, their

quantities, and their wireless radio capabilities.

The wireless network must serve all client devices simultaneously. Because Wi-Fi

leverages a shared RF medium, the network design and configuration must balance

requirements between all clients.

Identify the type of radio in each device (802.11b/g/a/n/ac).

Once the radio types is identified, determine the maximum Wi-Fi data rate that the

device is capable of achieving and on what channels and bands.

The maximum data rate is important for determining how fast a client can transmit

and receive data, which impacts the amount of airtime utilized to achieve the target

application throughput level and overall network capacity planning.

The channel and band support is important for determining whether or not DFS

channels can be used and for understanding the effectiveness of band-steering.

Next, determine the maximum application throughput that each type of wireless client

device that will be on the network can achieve.

Due to various sources of network overhead, the maximum Wi-Fi data rate does not

represent the actual application throughput that can be achieved.

To estimate the maximum amount of TCP/IP throughput that a client is capable of

achieving, the amount of network overhead must be determined either through live

network testing under load or through an educated assumption. It is common for Wi-

Fi networks to have between 40-60% overhead.

Estimating Access Point Throughput

The estimated aggregate throughput for an AP can be calculated as follows:

Maximum PHY rate * % of Overhead – Loss from interference (%)

As discussed earlier, TCP/IP networks often have as much as 40% overhead. This is

subtracted from the raw available throughput to yield a clean RF number. However, high

density venues will see this number reduced due to collisions. This number is hard to pin

down, but for these calculations 35% is a reasonable place to start.

The average expected throughput for an AP radio in the Undercroft Lecture Theatre is:

Bandwidth requirement per Application

Applications Nominal Throuput

Web access 500Kbps

Audio (Pandora, Apple

Music, Spotify)

100Kbps

Video (YouTube, Netflix,

Skype, FaceTime,

Hangouts)

1Mbps

File sharing and Printing 1Mbps

The total nominal throughput is 2.6Mbps.

The average expected throughput for an AP radio in the lecture theatre is:

72.2 Mbps – (72.2 Mbps* .40 %) = 43.3 Mbps – (43.3 Mbps *.35) = 28.12 Mbps

These numbers shown above are per radio. The lower number (2.4 GHz) is specifically called

out here. 5 GHz radios should expect a slightly higher number.

When many APs are able to influence one another, such as in a very high-density

deployment, the noise floor will rise. The same type of increase comes from the higher

number of end user devices. The result is not all the user devices are able to achieve the

highest modulation rate due to the noise floor increase and/or they are further away from the

AP than the others. The resulting AP capacity will be a function of the blended rates of each

end user devices modulation rate resulting in the weighted average.

43.36 Mbps – (43.3 Mbps* .40 %) = 26 Mbps – (26 Mbps *.35) = 16.9 Mbps

This average is per radio, so a dual-radio AP could be expected to deliver twice this amount

across two radios. However, since the second radio is 5 GHz and less subject to interference,

it should deliver a higher number.

The maximum transmission speed of a wireless device is typically listed as a reference but

the actual throughput that can be achieved will always be less. The following table lists some

common transmission rates:

Minimum PHY rate does not include management frames, which are typically sent at 1 - 2

Mbps. As noted, the rates listed here are PHY rates. A PHY rate is the maximum throughput

of raw symbols. This is not the same as application data, which is what is normally

considered throughput (or good put). Higher layer data such as Layer 2 TCP/IP and UDP/IP

traffic adds overhead and reduces the amount of actual bandwidth available for applications

such as web browsing and email. This overhead is a necessary part of any IP network.

Additional overhead from transmissions such as management frames on the wireless network

also reduce available client throughput. Management traffic includes AP beacons and

acknowledgements, which are vital of operation.

13 Estimating Clients per AP Capacity

The maximum number of client devices a single AP can support with the required KPIs is

then calculated as:

AP aggregate throughput / Minimum bandwidth per client

With the information so far, the maximum capacity for the example is:

Number of associated clients = 750

Estimated number of concurrent active devices = 99% of 750 = 750 approximate

Required throughput per client = 500 Kbps

Latency tolerance = high

RF environment = very high during peak usage

Percentage of retransmissions/loss due to interference = 35%

Estimated throughput per AP radio = 16.7 Mbps

These figures are then calculated:

Maximum clients per AP to meet capacity = 33 (16.7Mbps / 500Kbps per client)

Number of APs required to meet number of active clients = 22 APs (750/ 33)

Total APs for 750 associated devices = 15 (750 / 50)

Seats covered per AP = 13 (189 / 15)

The largest calculated number of APs, either for capacity or associations, is what is required

to meet the service requirement. Using these guides, 15 APs is the required number assuming

the client devices are distributed evenly across all APs

The only way to accurately estimate the weighted average capacity per AP is to do a

computer simulation of the venue and calculate the SNR of each AP and the entire service

area. Just estimating and using the peak value will yield to few APs and underestimating the

AP per capacity will drive the AP count higher, which will in turn further reduce the

weighted average per AP capacity.

14 Estimating additional APs

Determining how many extra APs are required beyond the minimum count requires

additional information:

• Distance from AP to client

• AP cell (coverage) size

• Additional coverage areas outside the Undercroft Lecture Theatre

Because venues such as Lecture Theatres are very large and very dense, APs should ideally

have small coverage areas. This increases performance and allows for narrower beam

antennas that can boost signal gain. More APs also increases the receive signal for clients

since there are more APs closer to any client location. This has the benefit of better SNR,

which is required for high performance and capacity. The directional antenna requirement is

driven by the need for higher signal gain due to higher installation locations. They also help

reduce interference. For more information on AP mounting strategies, please see section AP

Installation and Hardware. Distance from AP to Client In general, an AP should be mounted

as close to the clients as possible. RF signal strength is calculated as the inverse square of

distance so the signal degrades quickly as distance increases. A client that is 30 meters (98

feet) from an AP receives a signal that is only 1/4th that (-6dB) of a client 15 meters distant.

A large enough distance can reduce the signal strength to the point where a client cannot hear

it. This is particularly true if there is any background interference or noise.

Using this model of AP positioning based on its beam width helps determine the coverage

area for each AP. The need to get the APs closer is required to keep the AP foot print from

being too large. It can help to think of each AP supporting a particular spot or section of seats

within the lecture theatre itself. Each additional AP adds another group of seats until all are

covered.

15 Proposed Solution

Ultimate aim of this project is to provide WLAN services to Undercroft area and its

surrounding places. For serving the purpose, we divided our whole region into five sectors

where the black spots and the bleeding areas have been identified.

Extend the current Access points to higher antennas

Add new AP’s to serve the coverage of the designated area.

Proposed Design: Access points inside the Undercroft Lecture

Theatre

16 Channel Selection

In contrast to 2.4 GHz, 5 GHz has many more channels with which to work. As many as 21

channels can be received in Australia. But all 5 GHz channels are not created equally.

Limitations on maximum power for parts of the band are not of concern, but Dynamic

Frequency Selection (DFS) channels represent some challenges that must be addressed.

DFS was implemented so that APs and clients can share the band with radar devices. DFS

details how radar is detected and what should be done in the event of detection. APs

operating on DFS channels must first listen to a channel for 60 seconds to determine if there

is a radar present before transmitting any energy. If an AP is operating on a DFS channel and

detects a radar (real or false) it must shut down operations on that channel and abandon it for

30 minutes before that channel can be evaluated again for use.

The essential question for a high-density design is how many channels for each band will be

needed to match the client base? This can be a tricky question since even dual band capable

clients do not always select the faster 5 GHz band. Since bandwidth in 2.4 GHz is going to be

limited, 5 GHz must be relied on to reach the goal.

Dual band adapters have been shipping with most laptops for some time. This does not mean

that every laptop is a dual band client, but many are. Simply having a dual band client does

not guarantee that it will choose 5 GHz over 2.4 GHz. The Microsoft Windows operating

system defaults to a Wi-Fi channel search that starts with the 5 GHz channel 36 and continues

searching through all of the 5 GHz channels that the client is capable of. If no 5 GHz AP is

found then it will continue the search in 2.4 GHz starting at channel 1. Unless the Windows

default is changed or the user has chosen a third party Wi-Fi utility to set spectrum preference

to 2.4 GHz, the client radio will first try to associate to a 5 GHz AP. Apple Computer’s latest

release for Atheros and Broadcom chipsets also searches 5 GHz first.

17 AP Mounting Points

The APs are mounted to be as close to the seating as possible, covering the target number of

seats (coverage zone) and at the same time are positioned such to direct the energy away from

other APs.

Never mount the AP at the back of the venue pointing towards the back of the clients. As

stated earlier, the body loss is much higher than free space loss, so the signal from the AP

will propagate across the venue at a much higher signal level than it will to those seating

nearby with their backs turned.

In reality, the AP might not be able to be installed at the ideal position. This is usually

because there is no place to mount the AP at that spot or the AP is partially obstructed.

Sometimes this can be overcome with a higher gain antenna; other times there is no choice

but to select a different location. The only way to accurately assess this is with an on-site

survey of the physical structure. A survey will take into account the available mounting

locations, distance, line of sight to seating areas, and construction materials.

18 AP installation

As a general guideline, the following will hold true for most high-density Wi-Fi installations:

Very large venues will require small AP cells to maximum signal quality.

Directional or narrow-beam antennas are an excellent choice when density is very

high and coverage cell size is small – better signal and less interference.

Indoor APs are good choices for interior spaces such as suites, meeting rooms and

non-public areas such as offices.

Install APs as close to ideal locations for best signal quality with the least interference

(isolate the AP signal).

Non-optimal choices can still work well if planned correctly.

19 Budget Estimation and Financial Analysis

Cisco Aironet 802.11ac

Indoor Access Points

Most advanced carrier-grade indoor Wi-Fi AP

802.11ac dual-band (2.4 and 5 GHz) radios

Industry’s only 4x4, 3-spatial-stream AP

1.3 Gbps (5 GHz) WLAN RF data rates

High client density HD Video/VDI 802.11ac

Power: AC, DC, Cable, UPOE, PoE-Out (802.3at)

4G LTE coexistence

Module option: Investment protection and future proofing

Controller-based or standalone operation

Cost and Budgeting for the new Design

Line

Number

Item Name Description Quantity ListPrice Extended

List Price

1.0 Cisco Aironet 3700e

series antenna with

external antenna

802.11ac Indoor

AP

7 $3,000.00 $21,000.00

1.0.1 CON-SNT-XXXX License to

maintain the

802.11ac Indoor

APs

7 $341.59 $2391.13

1.2 Cables CAT6 AP to Switch,

Switch to

controller,

Switch to router

10 $350.00 $3,500.00

1.3 Labour Fixing APs,

cables etc

2 $700.00 $1400.00

1.4 Sai Eshwar Site Survey and

Design

1 $3,000.00 $3,000.00

1.5 Qaiser Tanveer Project Manager

and planning

1 $3,000.00 $3,000.00

1.6 Sai Shyam Project design 1 $3,000.00 $3,000.00

1.7 Micelleneous In case of

emergency

$10,000.00 $10,000.00

$47

,291.13

20 Project Implementation

This section will cover all the technical aspects of our proposed design. Each section briefly

describe about different types of specifications and the network devices used.

Before getting into the design implementation, we had thoroughly studied and analysed the

basic standards that need to consider before designing any of the wireless network. The

following points gives a quick overview of the studies and analysis done for implementing

the design.

For designing any wireless network the main aspect is to choose the modes of wireless.

Wireless network can be design on two different modes

Ad-hoc [IEEE name: Independent Basic Service Set (IBSS)]

Infrastructure [IEEE name : Basic Service Set (BSS)

Our proposal design is mainly influenced with the Infrastructure mode of wireless. The main

reason behind not choosing the Ad-hoc mode is its transmission limitations. With Adhoc

mode transmission can only be done within same transmission range i.e. within the same cell.

However, Infrastructure mode of Wireless design makes use of Access Points for its

communication. The access points acts as a bridge and transfers all communication to the

appropriate network.

OPNET Implementation:

For the simulation, we are using OPNET (Optimized Network Engineering Tool). This tool is

used for simulation, performance analysis of communication networks, computer systems and

applications. It also creates a great platform to execute simulations and analyse the output

data.

In OPNET, we basically start building the Wi-Fi networking model by creating a project and

working on the model at network layer. We are creating two scenarios, one with the existing

design and one with the proposed design by putting in Access Points (APs) accordingly as a

wireless router to transmit wireless signals, various number of work stations according to

different scenarios. The AP s is connected to the switch which is then connected to a server

which provides applications used for the workstations. Work stations are associated with the

profiles in order to use the applications. This is done by defining applications and profiles by

adding a node to each.

Important attributes changed for each node:

Access Point :

Node Model: wlan_ethernet_slip4_adv

Wireless LAN Parameters: BSS Identifier: <Unique ID for each access point>

Access Point Functionality: Enabled

Data Rate: 54 Mbps

Transmission Power: 0.005W

Workstation :

Node Model: wlan_wkstn_adv

BSS Identifier: same level number as the associated AP

Supported Application: varies correspond to different scenarios

Supported Services: All

Access Point Functionality: Disabled

Data Rate: 54Mbps

Transmission Power: 0.005W

Switch :

Node Model: CS_C3548XL_ae48_adv

Server :

Node Model: ethernet_server_adv

Application Supported Services: All

Application :

Node Model: Application Config

Application Definitions: 4 (Email-Heavy, FTP-High load, Http- High Load)

Profile :

Node Model: Profile Config

Profile Configuration: Choose the applications that correspond to different scenarios

Network Simulation: Scenarios for Undercroft lecture Theatre

Delay for scenario 1 and 2:

Node AP Workstati

on

Applicati

on

Profile Switch Server

Node Icon

Scenario 1 2 750 1 1 1 1

Scenario 2 7 750 1 1 1 1

From the above simulation result, we can analyze that the delay is maximum in the case of

scenario 1 which is when 750 active devices are accessing 2 APs and minimum in the other

case when 750 active devices are accessing 7 APs. We can conclude from the above

performance analysis that delay increases when the load is high on a single AP instead when

the load is balanced amongst 7 Aps, the delay seems to be balanced better in the high density

areas of the lecture theatre.

Throughput for scenario 1 and 2

As the number of workstations increases, the throughput also increases and it is evident from

the above figures. The throughput can be monitored by setting in proper inter packet arrival

rate and also modifying the configurations and operating conditions which affect the peak

throughput performance and efficiency of the system.

21 Schedule Estimation and Work Breakdown Structure

The estimated time for this project to be completed is about three months. The total working

time is 70 days.

Work Breakdown Structure1.0 Planning (15 days) 1.1 Project Planning 1.1.1 Research Background about the wireless technology

1.1.2 Overview of the Problem 1.2 Define project Scope 1.2.1 Scope of Initial Release

1.2.2 Scope of subsequent release 1.3 Define Business Case 1.3.1 Risk Analysis

1.3.2 Stakeholder Analysis

1.3.3 Cost & Benefits Analysis 1.4 Estimate Project Schedule 1.4.1 Create Work Breakdown Structure

1.4.2 Make stakeholder presentation

2.0 Design (25 days) 2.1 Analysis 2.1.1 Identify requirements 2.1.1.1 Define non-Technical requirements 2.1.1.2 Define Technical requirements 2.1.1.3 Identify the existing Wireless Network 2.1.1.3.1 Site Survey 2.2 Design Document 2.2.1 Create proposed design diagram 2.3 Prototype of Design 2.3.1 Simulate the design using OPNET

3.0 Implementation (30 days) 3.1 Implement the wireless network design

3.2 Testing

22 Communication Plan

Group meeting 1 (04/08/15 at 12:00pm~3:30 pm)

The goal of meeting

1. Getting to know the team members

2. Notifying each group member’s role

Result of meeting

1. Assign the group member

a. Qaiser - Project Manager (Communication log, guideline, Project role)

b. Eshwar– Project designer (Specialize on existing design and future plan)

c. Shyam – Project Secretary/ Network Specialist (Overall project role)

2. Collaboration tool – our group use Drop Box

Group meeting 2 (11/08/15 at 12:00pm~3:30 pm)

The goal of meeting

1. Preparation of introductory documents

2. Gathering information related to project

3. Start-up on the documentation of the project

4. Discussion on project scope

Group meeting 3 (18/08/15 at 12:00pm ~3:30 pm)

The goal of meeting

1. Activity assigned to the team for the site survey at Undercroft area

2. Analysing the prepared introductory documents for the project management plan

Group meeting 4 (25/08/15 at 12:00 pm~3:30 pm)

The goal of the meeting

1. Activity assigned to the team for the site survey

2. Compilation of the documents, final analysis.



1. Site survey using different softwares (Ekahau, VisiWave)

2. Compilation of the documents, final analysis.



1. Site survey using different softwares (Ekahau, VisiWave) – Redo, wrong

information from the clients



1. Site survey and survey results generation



1. Compilation of the documents and redoing the parts that were asked to be corrected

by the clients and supervisor



1. Getting familiarised by the OPNET tool

2. Budget analysis for the proposed design



1. OPNET simulation

2. Focused on the proposed design and bandwidth calculations for high density



1. Compilation of the documents, final analysis



1. Compilation of the documents, final analysis

2. Preparation for the final client presentation

23 Bibliography

[1] Australian University Deploys High-Density Wireless Network 2012PerthCisco

[2] Best Practices for Wireless Site Design2007Air Magnet

[3] CAMPUS LAN DESIGN GUIDE2010Juniper Networks

[4] CAMPUS NETWORK REPORT2011Austin, TexasInformation Technology Services

[5] Design and deployment of outdoor mesh wireless networks July 12, 2011Las VegasCisc Live

[6] Designing Basic Campus and Data Center Networks2008Cisco

[7] http://www.cisco.com/en/US/products/hw/wireless/index.htmlCisco

[8] Planning a Wireless Network January 2006ProCurve Networking by HP

[9] Site Survey and RF Design ValidationVoice Over Wireless LAN (VoWLAN) Troubleshooting Guide

Documents

CSE5 ITP High Density Wireless Design REPORT