Table of Contents
Advertisement
2. Video Network Designing
2.2. Bandwidth Requirements
The bandwidth calculation consists of two components:
▪
Required bandwidth of the streams (up to 2 streams per endpoint)
▪
Uplink bandwidth
The following sections give the details about these components.
2.2.1. Stream Bandwidth Requirements
UBEX transmitters have 2x HDMI 2.0 input ports which can receive two video streams for transmission to
the receiver. The required bandwidth for the stream is calculated from the resolution, the color space, the
refresh rate, and the loss ration of the video packeting (~5%).
Bandwidth Calculation
The correct formula:
X
x Y
x fps x ColorDepth x VideoPacketizingLossRatio = Total signal bandwidth
ACTIVE
TOTAL
Parameters:
Parameter
X
Number of the columns of the active resolution
ACTIVE
Total number of the lines including the blanking
Y
area
TOTAL
fps
Refresh rate
ColorDepth
Color depth
The ratio of the packet loss due to the packeting
VideoPacketingLossRatio
and the protocol
For the exact calculation you should know the total resolution of the stream because the transmitted number
of pixels are not equal with the active pixels which are finally displayed on the receiver side. The cause is the
blanking area where the embedded audio and other information travels with the HDMI signal.
INFO: The bandwidth calculation in the case of
the HDMI pipes count with the peak bandwidth
which is the summary of the video burst.
If the stream information is unknown to the
designer, to get the information of the active
resolution the Frame detector of Lightware is a
useful tool. The Frame detector is available in
our control software, in the Lightware Device
Controller (LDC), it can be downloaded from the
website www.lightware.com.
Example
Description
(4K UHD 60 Hz 24 bit)
3840
2250
60 Hz
24 bit
1.05663
Frame detector in the LDC software
Installation and Network Setup Guide for UBEX
Let's see an example:
I want to transmit a UHD (3840x2160@60 Hz) HDMI signal which is received on the HDMI input 1 port of the
UBEX transmitter.
Based on the formula the calculation is the following:
3840 x 2250 x 60 x 24 x 1.05663 = 13 146 167 808 = 13.15 Gb/s
This is the required bandwidth for the Stream 1 from the HDMI input 1 port. The HDMI input 2 receives an
1080p60 video, the required bandwidth is 3.29 Gb/s. The summary of the two values gives the final number
of the required signal bandwidth for the video streams.
4K PC
Blu-ray player
The signal bandwidth which is transmitted over the SFP+ ports is measured with the average bandwidth which
counts with active resolution lines instead of the total resolution lines.
2.2.2. Endpoint Uplink Bandwidth Requirements
UBEX endpoints support video over an optical fiber SFP+ network connection up to 20 Gbps which means
2x 10 GbE SFP+ slots. The 20 GbE can ensure transmitting
one 4K60 and one 4K30 signals, or
▪
▪
2x 4K30 signals, or
▪
one 4K60 and one 1080p60 signals together and losslessly.
No compression, no latency, every single bit is received as it is transmitted.
Input 1: 4K60
Input 2: 4K30
Input 1: 4K30
Input 2: 4K30
Input 1: 4K60
Input 2: 1080p60
TCP/IP conversion
Link aggregation
MAIN MENU
TX
Ports
EDID
System status
System settings
UBEX transmitter
Bandwidth of the input streams for UBEX transmitter
MAIN MENU
TX
Ports
EDID
System status
System settings
UBEX transmitter
B
A
B
A
MAIN MENU
TX
Ports
EDID
System status
System settings
UBEX transmitter
MAIN MENU
TX
Ports
EDID
System status
System settings
UBEX transmitter
Uplink bandwidth schematic
6
7.8 + 7.9 =
15.7 Gbps
Optical / DAC
B
A
B
A
B
A
B
A
B
A
B
A
B
A
B
A
L3 switch
Advertisement
Table of Contents
