IP Conversion of Broadcasting 1…

Leader Electronics Corporation Technical Information Series Vol.04

01

Background

02

The Technologies Supporting IP Transmission

03

Basic Knowledge about Communication

Overview

The content of this document is as of July 2020.
The company and product names in this document are trademarks orregistered trademarks of their respective holders.

IP Conversion of Broadcasting 1

01

Background
Overview about IP transmission

Overview
Until now, in broadcast stations, from video production to transmissions, SDI (Serial Digital
Interface) has been operated mainly, which is an industry specific standard. But in recent years,
resolution (2K→4K/8K), bit depth (8bit→10bit/12bit), and frame rate (60p→120p) have been
improved. In other words, as the image quality has been improved, it need to process more andmore amount of data. As a result, some problems have become apparent such as the number of
BNC cables and transmission distance.
Therefore, IP (Internet Protocol) technology are attracted attention. The cables for IP are lightcomparing to BNC cable so we can extend the transmission distance, and possibly reduce thecost in the future because the IP technology is making progress dramatically. In addition, with
PTP, the Black Burst signals (BB) is no longer necessary and we can construct more flexible
systems, so it has become widely used in broadcasting industry.

Comparing SDI with IP
Transmission Speed
In 1990, SD-SDI (270Mbsp) was defined. At that time, the Ethernet transmission speed was about
10Mbps which is significantly insufficient for broadcasting. Therefore, in Broadcast stations, SDI,
which is the only standards using coaxial cables, has been applied for a long times. However thetransmission by coaxial cables is coming up to the limit because the videos have gradually
evolved to 1080i (1.5Gbps), 1080p (3Gbps), 4K/30p (6Gbps), 4K/60p (12Gbps). And we should
predict that 8K is become prevalent in the future. On the other hand, the Ethernet has grown
rapidly in contrast to SDI, with 1 Gbps in 2000, 100 Gbps in 2010, and 400 Gbps as of 2019, andmore in the future.

Cost
SDI requires dedicated instruments due to industrial unique standards. And equipment are
required update every time developed new formats. However the costs tend to be expensive due
to its small market. On the other hand, IP is expected to dramatic cost down because we can use
highly versatile instruments such as switching hubs.

Multiplex
In SDI, one signal is transmitted by one cable. Against that, in IP, multiple signals can betransmitted by one cable. For example, when we use 100 Gbps network, more than 60 HD-SDI(1.5 Gbps) signals can be transmitted by one cable. It can also be supported format expansion
such as 4K and 8K. In addition to video signals, control signals, synchronization signals,
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IP Conversion of Broadcasting 1

intercoms, and all shooting data can be transmitted via IP, making it possible to reduce thenumber of cables and equipment.

Bidirectional
Bidirectional communication is available in IP unlike unidirectional communication in SDI with
fixed inputs and outputs. Therefore, we are only required to connect each equipment toswitching hub, it makes possible to construct high flexible systems.

Connection ImageFor SDI, each equipment is connected in processing in order. To synchronize each equipment,
they require the external sync signal.
Since SDI is unidirectional communication, basically we only connect each equipment to output
images without any special settings.

Figure | Connection image for SDI

On the other hand, IP is simply constructed with only connecting switching hub to eachequipment. Furthermore, using PTP, which is synchronized protocol for IP, it is also not required
the external sync signal.
Since IP is bidirectional communication, we have to construct the setting for each equipment to
output images.

Figure | Connection image for IP

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IP Conversion of Broadcasting 1

02

The Technologies Supporting IP transmission
The technologies and the standards for IP transmission

Connections
In SDI, we use BNC connector and BNC cables for video signals transmissions. In IP, we mainly use
the port and fiber-optic cables called SFP. In this section, we will explain the connections using
fiber-optic cable.

SFP
SFP is an abbreviation for Small Form-factor Pluggable. We usually connect the SFP port to thefiber-optic cable through the SFP transceiver. The SFP transceivers can convert the electricalsignals from the equipment side and the optical signals from the cable side mutually.

Figure | SFP connection

SFP transceivers has several types several types as below classified by the network transmission
speed. Here, available SFP transceiver type could be different by the equipment even if its
appearance are similar, so we have to take care for that when selecting them. In addition,transmission speed of the SFP receiving ports are required to be same as that of SFP transmission
port.
SFP port

SFP transceiver

Transmission speed

SFP

SFP

1Gbps

SFP+

10Gbps

SFP28

25Gbps

QSFP+

40GbpsQSFP28100Gbps

QSFP

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Fiber-optic
In optical communication, the cable which transmits the signals is called fiber-optic. A fiber-optic
consists of two parts. One is "core" through which signals transmit, the other is "clad" which
confines signals inside the core. Optical signals are transmitted by total reflection at the interface
between core and clads. Fiber-optic cables can transmit a large amount of data at high speed
over long distances. However we need to take care to handle fiber-optic cables because the coreand clad are usually made of glass.
Fiber-optic cables are roughly categorized MMF(Multi Mode Fiber) and SMF(Single Mode Fiber).
Here, "Mode" refers to the way that optical signals are transmitted.
MMFs have a large core diameter of 50 μm or 62.5 μm and can transmit optical signals in
multiple modes. But they could also degrade the signal and lose data. They are cheaper thanSMF, but are not suitable for long-distance communication. For example, in the case of
10GBASE-SR standard (10Gbps, MMF), the transmission distance is up to 300m.

Figure | MMF

SMF has a small core diameter of 9.2 μm, and signal attenuation and deterioration aresuppressed by transmitting optical signals in only one mode. It is more expensive than MMF, but
it is suitable for long-distance communication. For example, in the case of 10GBASE-LR standard(10Gbps, SMF), the transmission distance is up to 10km.

Figure | SMF

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Packetization for SDI Signals
In this section, we will explain the standards when packetize uncompressed SDI signals. See moredetails, separate volume “Content edition”.

Overview
In 2012, SMPTE ST 2022-6 was stipulated as the standard of packetization for uncompressed SDI
signals. SMPTE ST 2022-6 is the system that is packetized the entire SDI signal. And it supports up
to 3G-SDI.

Figure | Image of SMPTE ST 2022-6

In this standard, the data of video, audio, and auxiliary are mixed in one packet. So it was notefficient for receiving individual factor signal. Therefore, from 2017 to 2018, SMPTE ST 2110-20,
which packetizes video data, SMPTE ST 2110-30,

which is packetizes audio data, and SMPTE ST

2110-40, which is the standard packetized auxiliary data, were stipulated.

Figure | Image of SMPTE ST 2110

Moreover, SMPTE ST 2110 can synchronize with high accuracy by using PTP, which is thesynchronization protocol stipulated in SMPTE ST 2059.

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Standards
SMPTE ST 2022
SMPTE ST 2022 consists of seven standards from 2022-1 to 2022-7.In this section, we will explainfrom 2022-5 to 2022-7. These are related to uncompressed SDI signals.
Standard

Name

Overview

SMPTE ST 2022-5

Forward Error Correction forforward error correction for 2022-6

Transport of High Bit Rate Media
Signals over IP Networks (HBRMT)SMPTE ST 2022-6

Transport of High Bit Rate Media

Packetization forthe entire SDI signal

Signals over IP Networks (HBRMT)SMPTE ST 2022-7

Seamless Protection Switching of

Seamless signal switching for redundant

SMPTE ST 2022 IP Datagrams

transmission lines

SMPTE ST 2110
SMPTE ST 2110 consists of six standards from 2022-10 to 2022-40.And these generic name is"Professional Media Over Managed IP Networks".
SMPTE ST 2110 is not included the specification for error correction and signal switching. But wecan use SMPTE ST 2022-7.
Standard

Name

Overview

SMPTE ST 2110-10

System Timing and Definitions

Timings and rules for the entire systems

SMPTE ST 2110-20

Uncompressed Active Video

Packetization for the video data

SMPTE ST 2110-21

Traffic Shaping and Delivery Timing

Transmission timings for video data

for Video
SMPTE ST 2110-30

PCM Digital Audio

Packetization for AES67 format audio
data

SMPTE ST 2110-31

AES3 Transparent Transport

Packetization for AES3 format audio data

SMPTE ST 2110-40

SMPTE ST 291-1 Ancillary Data

Packetization for auxiliary data06

IP Conversion of Broadcasting 1

PTP
In this section, we will explain PTP (Precision Time Protocol), which is the protocol forsynchronizing on IP networks. See more details, separate volume “synchronization edition (under
editing)”.

Overview
PTP is the protocol that substitutes for external sync signal (Black Burst). PTP synchronizes ofvideo or audio by accurately adjusting the time of the equipment on the network. PTP used invarious situations, not only the broadcasting industry but also the telecom and the financial
industry.
NTP (Network Time Protocol) is the time synchronization protocol, too. Until now, NTP had beenused widely. However, the accuracy of NTP is 1 millisecond, while the accuracy of PTP is about 1
microsecond. So PTP makes it possible to synchronize more accurate than NTP.
For your information, the broadcasts require the synchronization accuracy 200 nanoseconds to
300 nanoseconds.

Standards
IEEE 1588
This is a fundamental standards for PTP, and there are two. “v1” was specified in 2002, and “v2”as specified in 2008. But v1 and v2 are not compatible.
Standard nameName

Overview

IEEE 1588-2002

IEEE Standard for a Precision Clock

Adopted by Dante (network audio(v1)

Synchronization Protocol forstandard)

Networked Measurement andControl Systems
IEEE 1588-2008

IEEE Standard for a Precision Clock

Adopted by SMPTE ST 2022-6,SMPTE ST(v2)

Synchronization Protocol for

2110, and AES67

Networked Measurement andControl Systems

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SMPTE ST 2059
This is a PTP standard adapted for broadcast equipment.
Standard nameName

Overview

SMPTE ST 2059-1

Generation and Alignment of

How to calculate for video and audio

Interface Signals to the SMPTE Epochphase starting from the SMPTE epoch.

SMPTE Profile for Use of IEEE-1588

SMPTE profile when used IEEE 1588 in

Precision Time Protocol in

broadcast.

SMPTE ST 2059-2

Professional Broadcast Applications
SMPTE EG 2059-10

Introduction to the New

Introduction and usage examples for PTP

Synchronization System

Control
In this section, we will explain the standards for controlling networks. See more details, separate
volume “Control edition (under editing)”.

Overview
Above as packetization for SDI signals and the PTP are conversions of conventional SDI signals to
IP On the other hand, the control is a peculiar element of the IP conversion. In this section, we
will explain that IS-04 and IS-05 in

NMOS(Networked Media Open Specifications), which isestablished by AMWA(Advanced Media Workflow Association).
AMWA refers the international organization which standardize control systems. NMOS refers thestandard control standards.

Standard
IS-04 (Discovery and Registration)
This standard is for discovery and registration of the equipment on networks.
The following API (Application Programming Interface) is provided.
・NodeAPI・QueryAPI
・RegistrationAPI
IS-05 (Device Connection Management)This standard is for management for connection between devices.
The following API (Application Programming Interface) is provided.
・ConnectionAPI

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03

Basic Knowledge about Communication
About basic knowledge of communication required for IP transmission

IP
IP is an abbreviation for Internet Protocol, which is a mechanism for subdividing the data you
want to send into a constant size packets and transmitting them over a network.
Subdividing into packets makes it avoid to occupy the network for long times and minimize
retransmission due to error occasion.
On the receiving side, you can obtain original data by restoring the packet data.

On the other hand, IP is said low reliable protocol. Because IP packets are not arrived in receiverside in the right order or are lost the data during transmitting. To prevent them, TCP/IP formats,which are combined IP with TCP (Transmission Control Protocol), are used widely.
(However, in broadcast field, UDP is used instead of TCP.)

ProtocolProtocol means "Rule". And The "P" in "IP" is an abbreviation for protocol. Therefore the case of"IP", it indicates "the rules when using internets".
Protocol has various types besides IP. And they are defined by organizations such as IETF
(Internet Engineering Task Force).

Figure | One example of the protocol

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PacketIn communicating mainly by IP, packets refer to the data subdivided into a certain size. The
packet consists of IP header and data. The IP header has various information related to the data.
For example, in the case of an IP packets, they indicate the data with an IP header attached. The
IP header has various information the IP address, etc.

Figure | Packet

In the case of a TCP, the segment indicates the data with a TCP header attached. But, they arealso called packet. So in this document, we will call them packet.

Figure | Segment

In the case of a UDP, the datagram indicates the data with a UDP header attached. But, they arealso called packet. So in this document, we will call them packet.

Figure | Datagram

As a supplementary explanation, in the case of an Ethernet, the frame indicates the data with an
Ethernet header and the FCS (Frame Check Sequence) attached. This FCS indicates the attacheddata to detect errors.

Figure | Flame

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Encapsulation
One packet consists of the header and the data. We reckon them as one data, and attach
another header. This is called encapsulation.
For example, the TCP packets consist of the TCP header and the data. And we reckon them as
one data, and attach the IP header.
Furthermore, removing the header from the packet and retrieving the data is called
decapsulation.

Figure | Encapsulation

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OSI Reference Model / TCP / IP Model
The following is a standardized communication mechanism for connecting various network
devices to each other. OSI reference model are classified the functions required forcommunication into seven layers. They are almost not used actually, despite important concept
to know the communication mechanism. On the other hand, TCP/IP model consisted of four
layers are used widely.
They has different contents. But both models have the layerized function, each layer is
independent. The transmitting side sends data from the upper layer to the lower layer, and thereceiving side passes the data received in the lower layer to upper layer. With this,communications are established.

Figure | OSI reference model / TCP / IP model※ There are various theories about supporting OSI reference model ,TCP/IP model supports, and theprotocol accompanying each layers. In this section, we described one example.

In the below, we will explain the flow of data sending and receiving by using OSI reference
model. As an example, taking RTP (Real-time Transport Protocol), which is the protocol used forbroadcast. And we will use UDP, IP, and Ethernet as communications protocol.

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At first, we will explain the data sending.
The RTP header is added to the sending data, and they are passed to the transport layer (L4).

In the transport layer "L4", the UDP header is added, and they are passed to the network layer"L3". (Encapsulation)

In the network layer "L3", the IP header is added, and they are passed to the data link layer "L2".

In the data link layer (L2), an Ethernet header and FCS are added, and they are passed to thephysical layer (L1) and converted to "0" and "1" data for transmission.

At next, we will describe the data receiving.
The "0" and "1" data received at the physical layer (L1) are restored to the Ethernet frame format
and passed to the data link layer (L2).

At the data link layer (L2), the Ethernet header and FCS are removed and passed to the network
layer (L3). (Decapsulation)

At the network layer (L3), the IP header is removed and passed to the transport layer (L4).

At the transport layer (L4), the UDP header is removed and passed to the application layer.

You can see the data by removing the RTP header at the application layer.

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IP Address
IP Address is the abbreviation of Internet Protocol Address. This is a unique identification number
assigned each instrument connected to the internet or the LAN.
IP Address consists 32 bits, and they are shown as the formats from "0.0.0.0" to"255.255.255.255".These are called IPv4, and the total numbers of them are about 4.3 billion. But
the depletion of IP addresses has already become a problem. So the transition to IPv6 is
progressing.

IPv6 consists 128 bits, they are shown from "0:0:0:0:0:0:0:0" to "FFFF: FFFF: FFFF: FFFF: FFFF: FFFF:
FFFF: FFFF". IPv4 and IPv6 are not compatible. So we are required So we are required IPv6
supports for network equipment.

MAC Address
MAC address is an abbreviation for Media Access Control Address. They are unique identification
number and is assigned each equipment connected to the network. In principle, once assigned,these are not changed. They consists of a total of 48 bits and are shown from
"00:00:00:00:00:00" to "FF: FF: FF: FF: FF: FF". The first 24 bits are called OUI (OrganizationallyUnique Identifier), which is a unique number representing the manufacturer name. The latter 24
bits are the numbers assigned by the manufacturer for each product.
The total number of MAC addresses are about 70 trillion, and it is said that there is no concern
about depletion at this time.

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L2 Switch (Switching Hub, Ethernet Switch)”L2“ in L2 Switch refers second layer of OSI reference model, which isthe data link layer. L2

Switch is an equipment which operates on this data link layer. This judges destinations according
to MAC address and send the data to equipment only required.

Figure | L2 Switch

Moreover L3 Switch is an equipment which operates on network layer, which is third layer of OSI
reference model. This judges destinations according to IP address and send the data.
Furthermore the equipment which operates the physical layer, which is first layer of OSI
reference model, are refered the repeater Hub. It sends the received data to all equipment. If
received data is not for myself, the data are discarded. Currently, repeater hubs are not used sowell.

Figure | Repeater Hub

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About structure of the documents"Vol.4 IP Conversion of Broadcasting" has four parts in total. This documents is “Overview
edition”. Please take a look at the followings as well.
・IP Conversion of Broadcasting 1

Overview

Background, Technologies that support

IP transmission, Basic knowledge about communication* This document

・IP Conversion of Broadcasting 2

Contents

About SMPTE ST 2110

* Under editing

・IP Conversion of Broadcasting 3

Synchronization

About PTP

* Under editing

・IP Conversion of Broadcasting 4

Control

About NMOS

* Under editing

Address

2-6-33 Tsunashima-Higashi, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture 223-8505, JapanPhone+81-45-541-2123

Emailsales@leader.co.jp

URL

www.leader.co.jp/en

Published

April 8, 2021 Ver. 116