Wireless Presentation

Introduction

This chapter covers the primary components, common features, and best practices for planning, designing, and deploying wireless presentation for integrated AV systems.
A wireless presentation system consists of three key components:
  • Receiver is the image processor that receives presentation content via the network and outputs an AV signal
  • Source is the computer, tablet, or smartphone that transmits presentation content to the receiver device via a network connection
  • Network Infrastructure is the method of communication between the source device and the receiver device
Wireless presentation involves the transmitting of AV content using wireless connection between a source and receiver, via one of two methods:
Method 1 - Wireless Presentation via enterprise infrastructure
Mobile devices used for presentation in teaching and meeting spaces connect using Wi-Fi to deliver content to receiver devices typically connected to the network via an Ethernet interface (wired).
Transmitters and receivers may be a dedicated hardware device, a dedicated software application, or the screen share feature of a Unified Communications application.
Method 2 - Wireless Presentation via Point-to-Point systems
Point-to-point systems use a wireless connection directly between the source and receiver device. Point-to-point systems are often characterised by hardware transmitters and receivers. Connection is typically via an onboard Wireless Access Point (WAP) or using a proprietary RF modulation scheme.

Glossary of Terms

Term
Definition
AirPlay
AirPlay is a proprietary protocol stack/suite developed by Apple that allows wireless streaming between devices of audio, video, device screens, and photos.
Android
Android is a mobile operating system developed by Google and is designed primarily for touchscreen mobile devices such as smartphones and tablets.
API
A software program through which software may interact with an AV system component, third-party software, or sub-system.
Bonjour
Bonjour locates devices such as printers, other computers, and the services that those devices offer on a local network using multicast Domain Name System (mDNS) service records.
BYOD
Bring Your Own Device for teaching and meeting room AV presentations
DHCP
The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on UDP/IP networks whereby a DHCP server dynamically assigns an IP address and other network configuration parameters to each device on a network so they can communicate with other IP networks.
DNS-SD
Domain Name Server Service Discovery is the automatic detection of devices and services offered by those devices on a computer network. A service discovery protocol (SDP) is a network protocol that helps accomplish service discovery.
Receiver Device
A network-connected image processor that receives incoming image and audio data via the network, and outputs a signal via standard AV interfaces (HDMI, VGA, 3.5mm TRS audio etc.)
IEEE
The Institute of Electrical and Electronics Engineers (IEEE) is a professional association with its corporate office in New York City and its operations center in Piscataway, New Jersey. It was formed in 1963 from the amalgamation of the American Institute of Electrical Engineers and the Institute of Radio Engineers.
IGMP
Internet Group Management Protocol is a communications protocol used by hosts and adjacent routers on IPv4 networks to establish multicast group memberships.
IGMP Snooping
The process of listening to Internet Group Management Protocol (IGMP) network traffic to control delivery of IP multicasts. Network switches with IGMP snooping listen in on the IGMP conversation between hosts and routers and maintain a map of which links need which IP multicast transmission.
iOS
A mobile operating system created and developed by Apple Inc. It is the operating system that presently powers many of the company's mobile devices, including the iPhone and iPad..
IP Address
An Internet Protocol Address (IP Address) is used for network communication between computer devices
LAN
Local Area Network (LAN) is a network of interconnected computers within a building or department
Mac OSX
An operating system developed and marketed by Apple Inc.
mDNS
Multicast DNS (mDNS) protocol resolves host names to IP addresses within small networks that do not include a local name server.
Microsoft Windows
Microsoft Windows is a group of several graphical operating system families, all of which are developed, marketed, and sold by Microsoft.
Miracast
Miracast is a standard for wireless connections from devices (such as laptops, tablets, or smartphones) to displays (such as TVs, monitors or projectors), introduced in 2012 by the Wi-Fi Alliance.
RF
Radio frequency (RF) is the oscillation rate of an alternating electric current or voltage of a magnetic, electric or electromagnetic field or mechanical system in the frequency range from around 20 kHz to around 300 GHz.
Screen Mirroring
The main display and audio output of the source device is duplicated to the wireless presentation receiver device.
Source Device
A network-connected computer or mobile device (tablet, or smartphone) with software that enables the sharing of content via a network connection such as Wi-Fi.
SSID
An SSID (Service Set Identifier) is broadcast by wireless network stations in beacon packets to announce the presence of a network.
TCP/IP
A suite of communications protocols to connect computers on the internet and is the standard for transmitting data over networks.
UC
UC (Unified Communications) is a broad term that covers any communications that can be performed over a network, including audio and video conferencing, voice/telephony, data sharing, screen sharing, instant message, presence information, or other integrated communication functions.
VLAN / Subnet
Virtual Local Area Network is a logical partition of a physical LAN. Assigning groups of computers to VLANs allows for compartmentalisation and segregation of network traffic and may also improve network security.
Wi-Fi
Wi-Fi is a family of radio technologies that is commonly used for the wireless local area networking (WLAN) of devices which is based around the IEEE 802.11 family of standards.
WLAN
A wireless LAN (WLAN) is a wireless computer network that links two or more devices using wireless communication to form a local area network (LAN) within a limited area such as a home, school, computer laboratory, campus, office building etc.
Zero-configuration networking (zeroconf)
A set of technologies that automatically creates a usable computer network based on the Internet Protocol Suite (TCP/IP) when computers or network peripherals are interconnected.

Key Stakeholders

Below is a list of stakeholders commonly involved in the planning, deployment, and maintenance of a wireless presentation solution:
  • AV and ICT Teams - design of integrated technology, including security requirements
  • End Users - functionality, features, and user experience
  • Wired and Wireless Network Teams - active network equipment, cabling, patching infrastructure

Requirements Gathering

Use Cases

Wireless systems are often required to enable the:
  • presentation of computers and mobile devices to the AV system;
  • presentation of specific applications or windows to the AV system;
  • presentation of computers and mobile devices, including digital annotation/whiteboarding.
  • ability for presenters to be dynamic and mobile whilst presenting;
  • ability for audience members (including students and guests) to share their work;
  • sharing of content from personal devices where wired connections are not provided, or economically viable;
  • provision of a hardware-connection-agnostic solution for a variety of users and devices.

User Requirements

Below is a list of specific requirements that may need to be considered when planning for and designing wireless presentation systems. The list should be used as a guide and is non-exhaustive, but it is important to consider if:
  • Users need to mirror their screens via (these may be organisation and application-dependent):
    • native features of device operating system (e.g. AirPlay, Miracast et al); or
    • a dongle (USB, HDMI, DisplayPort, USB-C) for plug-and-play wireless presentation.
  • Users need to load files from USB storage for presentation (e.g. Microsoft Office documents, PDF, image files, video files etc.).
  • Users need to load files from cloud storage solutions (e.g. Dropbox, Microsoft One Drive, Google Drive etc.).
  • Content needs to be shared from wireless and/or wired networks.
  • Touch interactivity for whiteboard and annotation purposes.
  • Teacher / student applications where a single administrator manages multiple connected source devices to select which will at any time present to the AV system
  • Functionality to include multiple concurrent source devices to be presented simultaneously to one display/receiver device.
  • Functionality to include remote connections that may present over WAN or internet connection.
  • Source device authorisation and identification may be required (e.g. via Active Directory).
  • Guest users may require access to wireless presentation systems.
  • Secure connection and transmission of wireless content is required.
  • The solution has to be platform agnostic and compatible with all major computer and mobile device operating systems..
The next steps in selecting a wireless solution involve considering the preferred user experience and understanding the various solutions available to ensure the technical requirements of your organisation’s ICT architecture, design and operations staff are supported.

User Experience

Consider the following when designing the user experience for the wireless presentation system. Note that the options below can be used in conjunction with one another, where required:
  • Define what content the user may want to share:
    • Screen mirroring
      • The device’s operating system may have native functionality such as Airplay, Miracast, etc.
      • A proprietary application may need to be downloaded to access mirroring functionality
    • Application sharing or other product-specific features
      • Application window sharing, document sharing, whiteboarding etc.
      • A proprietary application will likely need to be downloaded to access product-specific features
    • USB dongle pre-loaded with software required for wireless presentation from a user laptop
    • HDMI / DisplayPort transmitter dongle for wireless presentation from any video device
  • Consider the available solutions on the market including hardware receivers, dongles and software solutions, where applicable. This will assist with the possibilities of the following steps.
  • Determine how the users wish to pair source devices with the wireless solution:
    • Receiver presents splash screen to user with instructions
    • Printed instruction guide on display within room
    • QR code is presented to users (compatible with above methods)
    • Receiver naming convention associates wireless presentation solution with room identifiers, users pair by selecting the receiver that matches the room and AV system they are using
    • Web browser application accessed by navigating to the receiver device IP address
    • User initiates screen sharing from their device
    • User presses button on dongle to begin presenting
  • Determine what happens when multiple source devices connect concurrently:
    • Most recently connected source device is presented - concurrent sharing not enabled
    • Attempts to present are prevented if a source device is already connected
    • Image becomes split/quad screen automatically
    • Admin must authorise presentation from connected source devices
  • Determine what level of security is needed:
    • Receiver device splash screen presents the connection method (see #3), and pin code required for connecting source devices
    • Encryption methods (e.g. 128 or 256-bit AES) may be required to meet security posture of organisation
    • Receiver device discovery via Bonjour and source device may select receiver device name from list
    • Connections authorised according to Active Directory (or similar) approved users
    • Hardware receiver device is also a wireless access point, source devices connect by first connecting to the SSID wireless network as created by the receiver device
When considering the above, always remember that in general the proposed solution must be as fast and simple as possible for the user to initiate and operate. Overly complicated or convoluted systems will often result in the wireless presentation system not being used at all, and thus quickly becoming obsolete

Wireless Presentation System Options

As can be seen from the use cases and specific user requirements of wireless presentation solutions, a myriad of applications can be supported, operating via both wired and wireless means. Two distinctions are important to draw before considering wireless system types for learning environments.

Comparison to AV-over-IP Systems

When mirroring a device’s screen, wireless presentation performs much like commercial AV-over-IP solutions where an encoded AV content data stream is transmitted over a network and decoded by a receiving device, often by a standard video codec (e.g. H.264).
Wireless presentation differs from AV over IP in the following ways:
  • Utilises wireless connection between source device and receiver
  • Typically longer latency when screen mirroring, which can cause an undesirable “laggy” performance (especially with full motion video)
  • Generally limited to computer and mobile devices via applications or native mirroring protocols when they are the source device (Wireless via WiFi only)
  • Can often include:
    • the ability to share applications and windows, as well as entire desktops
    • graphics processing capability for generating dynamic splash screens and overlays;
    • onboard storage for caching common document formats (Microsoft Office docs, PDF, JPEG images, and video files) for high-resolution presentation;
    • whiteboard and annotation capability

Point-to-Point Wireless Extender Devices

Some vendors have products designed to transmit a digital video signal over wireless between a dedicated transmitter and receiver device, effectively a wireless video extender set. This type of device is distinctly different to solutions based on WiFi and the feature set is typically limited to the transmission of AV signals from point to point via input connector on the transmitter and output connector on the receiver.
It is recommended to use a wired video connection instead of a wireless video extender device as a wired solution is far simpler and less susceptible to interference, or to cause interference to other systems.
Devices of this type often use an RF modulation scheme other than WiFi (IEEE 802.11) to transmit AV data, typically utilising the 2.4 Ghz and 5 Ghz RF spectrum. These devices often include a certificate of conformity to ensure they are legal to use within the RF spectrum of each country of sale, however they may not be suitable for operation within your organisation’s spectrum.
Where these devices can not be avoided, the team responsible for the wireless network must be engaged to ensure the technology is acceptable and supported within the organisational RF spectrum management plan, and vendor documentation must always be adhered to.

Key System Components

As previously stated, a wireless presentation system is composed of three key components:
  • Receiver is an image processor that receives content data via the network and outputs an AV signal to be shared via hardware device or software application
  • Source is the computer, tablet, smartphone or video device that transmits content data to the receiver device via a network connection
  • Network Infrastructure is the method of communication between the source device and the receiver device, including local wired and wireless networks, and may also include internet connection

Receiver Device / Software

A wireless presentation receiver is broadly an image processor capable of receiving video, audio, and control content data via a wireless, or network connection for presentation to an AV system. Wireless presentation receivers often have a combination of the following features:
  • May be compatible with common screen mirroring protocols such as Airplay, Miracast, et al
  • May be a stand-alone hardware appliance, built into a display device or a software application
  • May be a feature of a Unified Communications platform or classroom management software
  • Typically for presentation of documents, slideshows, photos, and videos.
  • Screen mirroring capability is available, though may vary in latency and resolution across solutions
  • Typically uses standard network protocols such as Ethernet, TCP/IP, UDP/IP, HTML, and Wi-Fi for establishing connections
  • Can generate dynamic graphics such as splash screen, overlays, or split screen
  • When idle (no source connections), may present a splash screen instructing users how to connect, or other information
  • Encryption may be supported for connection between source and receiver devices
  • Point-to-point systems may use proprietary wireless data stream technology or modulated RF

Source Devices

Depending on the wireless presentation solution used, a source device can fit one or more of the following descriptions:
  • A device that transmits AV content via wireless connection
  • A computer, tablet, or smartphone with network connectivity
  • A Unified Communications / web conferencing application with screen sharing support
  • Any device with a digital video output (when used in conjunction with digital video dongle / transmitter solutions)
  • May be a device provisioned and managed by ICT department, or may be a BYOD device with an unknown security configuration
  • May be compatible with common screen mirroring protocols such as Airplay, Miracast, et al
  • Capable of downloading and installing software required to wirelessly present to receiver device
  • Controls the operation of the receiver device

Network Infrastructure

Network infrastructure to support wireless presentation systems may include the following:
  • Active components that make up a network (network switches, wireless access points, wireless controllers, routers, firewalls, servers, et al)
  • Passive cabling components (cabling, outlets, patchbays, et al) to interconnect active devices
  • Configuration to allow device discovery, session management, network traffic, routing and security where required
  • Operational management to support network communications between receiver devices and source devices

Network Architecture Options

Wireless presentation systems have different network configuration and topology requirements which are important to understand and consider from an ICT architecture standpoint. Certain devices / approaches may be ruled out or need their configuration changed in order to be supported within your organisation.
  • Network topology and wireless solution may require:
    • Converged network (mixed use)
    • Dedicated VLAN and may allow select network traffic to reach AV over IP VLAN
    • Dedicated network switches ‘air-gapped’ from other network traffic
    • Source device connects directly to a wireless network created by a receiver device
    • Internet access may be required for Unified Communications-based solutions for source devices
  • Solution must support:
    • WiFi WLAN IEEE 802.11 protocol standards
    • Ethernet IEEE 802.3 protocol standards

Wireless Presentation Design Responses

Regardless of the solution or network architecture requirements, always refer to the product-specific wireless presentation deployment guide for detailed network architecture options and configuration requirements.
Engagement of organisational ICT and network teams responsible for network configuration and port security is paramount to successfully deploying a solution that works as designed and does not affect other users (e.g. through RF interference, compromised security etc.).
Prior to deployment of any solution, a thorough testing phase must be carried out to ensure the solution is fit-for-purpose for all the key stakeholders involved.
The table below describes common technical requirements and the associated design responses when deploying a wireless presentation solution:
Technical Requirement
Design Response
Unified Communications support
Wireless connectivity must be compatible with Unified Communications software to allow screen sharing to local and/or far-end participants, as well as recording.
  • Use in-built wireless screen sharing capabilities of Unified Communications software. Source device must be able to reach the internet or UC server (recommended approach)
  • Use digital video to USB conversion when hardware receivers must be utilised (higher cost and complexity )
AirPlay compatibility Apple laptops, tablets, and smartphones are natively compatible with AirPlay
  • Receiver device must support AirPlay
  • Allow AirPlay network traffic
  • Source devices must be on the same subnet as receiver devices
  • Allow mDNS, DNS-SD, and bonjour network traffic
Miracast compatibility
Android and Windows 10 laptops, tablets, and smartphones are natively compatible with Miracast
  • Receiver device must support Miracast
  • Allow Miracast network traffic
Product-specific features and software Each wireless presentation product may have features that are only available when running product-specific software
  • Software download and installation procedure must be defined and provided to system design team, support teams and end users
  • Software download and installation must be permitted for ICT-controlled devices
  • Software may be pre-installed to organisational devices
Product-specific network configuration
Each wireless presentation product uses different network protocols and TCP/IP ports
  • Allow product-specific network protocols and TCP/IP ports
  • Refer to deployment guide for product
Zero-configuration device discovery For ease-of-use, receiver devices will be visible on the network
  • Receiver devices host names should describe the presentation display (or room) with which they are associated
  • Source devices may need to be on the same subnet as receiver devices
  • mDNS, DNS-SD, and/or bonjour network traffic are likely required
Wireless presentation receiver on different subnet ICT security policy may require that receiver devices be on a different subnet to the user’s source devices
  • Network traffic must be routed between subnets
  • Receiver splash screen must show IP address, or domain name
Receiver devices receive dynamic IP addresses ICT security policy may require that receiver devices be given an IP address via DHCP server
  • Receiver splash screen must show IP address, or domain name
Receiver device may read/write documents from cloud service
Wireless presentation product-specific software allows connections to cloud storage services for document presentation
  • Receiver device must be allowed to access the internet
  • Cloud storage service account may require registration
No WiFi available, pair direct to receiver device
No wireless network may be available for users
  • Receiver device must feature Wi-Fi WLAN adaptor
  • Receiver device to create a WiFi network for user’s source devices to connect to
AV devices must not create WiFi networks
ICT security policy may require only ICT-managed WiFi networks be permitted on campus
  • Receiver device should not feature Wi-Fi WLAN adaptor; or
  • Wi-Fi WLAN adaptor must be disabled for receiver device
Guests on Guest WiFi must be able to use wireless presentation
ICT security policy may make a Guest WiFi network available for visitors
  • Use Unified Communications platform, or:
  • Source devices must be able to access receiver devices via the network.
  • Some devices may require source and receiver devices to be on the same subnet.
  • Receiver device may have two Ethernet interfaces (dual NIC), to accept connections from Guest network, and Staff network
  • Network configuration may be required to allow traffic between guest and receiver subnets
Remote management of receiver devices Remote management may be required to reduce effort when managing multiple devices
  • Receiver device must be connected to network infrastructure
  • Remote management PC must be permitted to connect to receiver devices over the network
  • Licensing may be required, check with vendor to ensure costs are understood and budgeted before deploying at scale
AV devices must not connect to network
ICT security policy may require that no AV devices be connected to the network
  • Use point-to-point AV wireless transmitter / receiver solution
  • Systems often use 2.4 Ghz or 5Ghz spectrum
  • Wireless network teams to be engaged to ensure technology is supported within organisational RF spectrum management plan
Point to Point Video Connection Wireless system may need to support point-to-point connection of digital video signals
  • Vendor solution may be required to allow digital video connections (e.g. HDMI) at source and receiver locations, where cabling unable to be run or uneconomical
  • Systems often use 2.4 Ghz or 5Ghz spectrum
  • Wireless network teams to be engaged to ensure technology is supported within organisational RF spectrum management plan
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