Ethernet

• The Basic Knowledge of Ethernet

• Types of MW Links

• ADAPTIVE MODULATION(AM)

• Ethernet over PDH(EOP)

• Ethernet over SDH(EOS)

• Cards supporting Ethernet in Ericsson Equipment(ETU2,ETU2B,ETU3,NPU3B,NPU1C, MMU2D,MMU2H)

• PDH-IME(Protocol for PDH)

• RL-IME(Protocol for packet links)

• Configuration of Ethernet on Ericsson MW equipments

• IP DCN concepts

Content

CSMA/CD

Key of media sharing: CSMA/CD

The terminal equipment continuously detects the status of the shared line and transmits data only when the line is free. If the line is busy, the terminal equipment waits until the line is free. If other equipment transmits data while the terminal equipment is transmitting data, the data then collides and the signals in the line are instable. When detecting the signals instability, the terminal equipment stops transmitting data and wait a while until the line is free.

1 2 3 4 5

INOUT OUTOUTOUT

Solution• Full duplex mode of the Ethernet port

• MAC address self-learning

The network connected by a HUB

is a collision domain.

Working Mode of the Ethernet Port

The configuration to each equipment in the access network brings too much work.

The configuration is also hard to maintain. What is the solution?

Full duplex

Type Optical/

Electrical

Compliant with Supported or Not

10/100M Electrical IEEE 802.3u Y

100M Optical IEEE 802.3u Y

1000M Electrical IEEE 802.3z Y

1000M Electrical - N

10G Optical - N

The system detects the auto negotiation

flag upon power-on. If auto negotiation is

allowed, the system reads the support

mode flag from the configuration register,

codes it and then sends it out via an idle

pulse. The sent coding format is called the

“base page”.

The system receives the base page from

the peer and compares it with the base

page it has sent, so as to find out the

intersection of the support capabilities and

select the optimal combination for

running.

duplex modeRunning rate Flow control

101001010111000101001101010101…...

Auto Negotiation

Standard Ethernet Frame Structure

• PRE: Guide byte ， 7 个 10101010 • SFD: Frame starting flag ，

10101011

64 – 1518 byte

Do you know why IP address is not fixed as MAC?

00000001 10111011 00111010 10111010 10111110 10101000

It means this is a multicast address.

Ethernet MAC Address• 00.e0.fc.39.80.34

– MAC address includes 48 bits and it is shown as 12 dotted hexadecimal notations

– MAC address is exclusive globally which is allotted and managed by IEEE. Every MAC address is composed of two parts. The first 24 bits part is the vendor code and the other 24 bits part is serial number

– If 48 bits are all “1”, it means the address is used for broadcast

– If the 8th bit is “1”, it means the address is used for multicast

The switch maintains a CAM table which decides the forwarding.（ Content － addressable memory ）：

MAC Egress set

1234.ABCD.00011234.ABCD.00021234.ADCB.0003 . .

{port1}{port2}{port3} . .

MAC Learning Function

Port-1 Port-3Port-2

PCA-1234.ABCD.0001 PCC-1234.ABCD.0003PCB-1234.ABCD.0002

After receiving a data frame, the switch

queries the CAM table by the destination

address to find the egress and then send

the data packet out of this egress set.

There is only one element in the egress

set in the case of uncast but may be more

than one element in the case of multicast.

1234.ABCD.0001 1234.ADCB.0005

MAC Egress set

1234.ABCD.00011234.ABCD.00021234.ADCB.0005 . .

{1}{2}{3} . .

Working Procedure of the Switch --- Forwarding

•Known unicast: The MAC address is forwarded at

the port.

•Unknown unicast: The MAC address is broadcast

at the forwarding port.

•Broadcast: The MAC address is broadcast at the

forwarding port.

•Multicast: The MAC address is forwarded at

partial ports according to the dynamic or static

multicast table.

MAC Egress set

1234.ABCD.00011234.ABCD.00021234.ADCB.0003 。 。

{port1}{port2}{port3} 。 。

MAC Address Forwarding (Switching) per the Sink Port

Port-1 Port-3Port-2

PCA-1234.ABCD.0001 PCC-1234.ABCD.0003PCB-1234.ABCD.0002

CAM Table Aging Time

• CAM table aging time– Each CAM item provides a timer, which decreases from a initial

value. Once this CAM item is used (the CAM table is searched for the item, which is used for forwarding the received data frames.), the timer is re-set. If the forwarding item is not used for a long time, the timer decreases to zero and the CAM item is deleted. The time of the timer is the aging time.

Ethernet frame forwarding scheme

• Storage forwarding (currently used)– The received data frames are stored in the buffer. The CRC check

and the check of the length of the packets are performed. After that, the CRC table is searched for forwarding the data frames.

• Straight through– After the headers of the data frames are received, the CAM table

is searched. According to the searching result, the data frames are forwarded.

SWITCH

Engineering Department

Marketing Department

Financial Department

10.110.10.010.110.20.0

10.110.30.0

1 2 985

MAC Egress set

1234.ABCD.00011234.ABCD.00021234.ADCB.0003 。 。

{port1}{port2}{port3} 。 。

VLAN

122 。 。

VLAN technology

Such frames are transmitted on the Trunk link. The peer

switch identify t the correct VLAN by the VLAN ID in the

802.1q frame and then forwards the frame to the ports in

the VLAN.

D_Addr S_Addr 802.1q L/T DATA

TYPE PRI/CFI/VID

NAME VLUE

TYPE

PRI

CFI

VID

8100

Priority

Used for the ring network

VLAN ID

802.1Q Frame format

VLAN technology

resolves the

broadcast problem

and enhances the

communication

security.

Prevent Broadcast Storm via VLAN

Port-1Port-2

Port-4

Port-3

PC-A PC-B PC-C PC-D

• Two switching devices transmit the VLAN ID information to each other to distinguish and isolate the

information of different sources.

•The VLAN ID of the equipment that communicates should be the same.

Application of VLAN

Equipment A of department A

Equipment A of department B

Equipment B of department A

Equipment B of department B

Switch two VLAN ID

•VLAN IDThe VLAN ID is carried by the Ethernet frame and identifies the VLAN for the Ethernet frame.

• PVIDFor a specific Ethernet port, the VLAN for it should be specified. The Ethernet switching is performed in the same VLAN.

• VLAN filter tableFor a specific Ethernet port, the VLANs allowed to pass the port should be specified. These VLANs are specified in the VLAN filter table. If a specific Ethernet port belongs to the VLAN, the Ethernet packets carrying the VLAN ID are allowed to pass the Ethernet port.

Key Concepts About VLAN

Packet

Port Tag Untag

Tag aware (In) Transmit transparently Discard

Tag aware (Out) Transmit transparently －

Access (In) Discard Attach default VLAN ID

Access (Out) Delete VLAN ID －

Hybrid (In) Transmit transparently Attach default VLAN ID

Hybrid (Out)

If VLAN ID is the same, delete

the Tag flag, otherwise

transmit transparently－

Dealing with VLAN ID

TYPES OF MW LINKS• TDM• HYBRID• PACKET RADIO

Advent of the IP Age

2G -> 3G -> 3G+ ->LTE, the backhaul of mobile base stations evolves from TDM to IP. Microwave transport networks evolve from the traditional TDM microwave network to the packet

microwave network.

BSC RNC

eNodeB eNodeB eNodeB

aGW

X2X2

NodeBNodeB NodeBBTS BTS BTS

Mobile Backhaul

TDM/ATM TDM/ATM/Eth. ALL IP

2000 1XDL:153.6kUL:153.6k

EV-DO(R0)DL:2.4MUL:153.6k

EV-DO(RA)DL:3.1MUL:1.8M

EV-DO(RB)DL:6.2-73.5MUL:3.6-27M

LTEDL:100MUL:50M

2 Gbit/sR99/R4DL:384kUL:384k

HSDPA(R5)DL:14.4MUL:384k

HSUPA(R6)DL:14.4MUL:5.76M

HSPA+(R7)DL:43MUL:11.5M

LTE(R8)DL:100MUL:50M

Mobile Evolution

CDMA2000

WCDMA

Packet in air

IDU

Real-timeReal-timeReal-time

Real-time

Real-time

TDM

based

TDM

IDU

Packet

based

TDM

ETH

TDM in air

Three Microwave Forms

Hybrid in air

ETH

IDUReal-time

Real-timeTDM TDM

Packet

ETH

Native

EOS

Native

Native

PW

TDM Microwave: PDH microwave is used for access; SDH microwave is used for convergence. Ethernet services are transmitted in the space through the EOS technology. It supports the fixed modulation scheme from QPSK to 128QAM, and features small

capacity.It is used in 2G and early stages of 3G networks.

Hybrid Microwave: Native TDM + Native Ethernet It supports the modulation scheme from QPSK to 256QAM and the AM function, and

features high bandwidth. It is used in scenarios where TDM and IP networks coexist at the initial stage of the

transition from 2G networks to 3G networks. At this stage, voice services are primary and data services are secondary among mobile services. Adding the packet switching capability to the original TDM microwave equipment is undoubtedly the preferred solution at the transition stage of the mobile transport network evolution. In this way, investment in original equipment can be protected and existing voice services can be transported.

Packet Radio: It is pure packet microwave. It supports the modulation scheme from QPSK to 256QAM and the AM function, and

features high bandwidth. It is used at the All-IP stage of 3G networks. The pure packet microwave is the best

choice for a carrier who needs to build a new mobile IP transport network.

Evolution of Microwave Transmission Network

• When microwave transport networks evolve towards packet transport networks inevitably, it is a most cost-effective solution for carriers to evolve microwave transport networks from traditional TDM microwave networks to hybrid microwave networks, and then to pure packet microwave networks. This solution combines strengths such as protecting investment in existing networks, flexible upgrade, and compatibility. If carriers need to build new mobile IP transport networks, the best choice is to use advanced pure packet microwave equipment to transport future All IP services.

TDM Microwave

• The PDH microwave refers to the microwave that transmits only the PDH services (mainly, the E1 services). During the transmission, the PDH microwave does not change the features of the PDH services. Unlike the conventional PDH microwave equipment, the RTN 900 V1R2 has a built-in MADM. The MADM grooms the E1 services to the microwave port for further transmission. Thus, the services can be groomed flexibly and seamless convergence between the optical network and the microwave network is achieved.

• The SDH microwave refers to the microwave that transmits SDH services. During the transmission, the SDH microwave does not change the features of the SDH services.

• Unlike the conventional SDH microwave equipment, the RTN 900 V1R2 has a built-in MADM. The MADM grooms services to the microwave port through cross-connections, maps the services into the STM-1-based microwave frames, and then transmits the STM-1-based microwave frames. Thus, the services can be groomed flexibly and seamless convergence between the optical network and the microwave network is achieved.

Hybrid Microwave

• The Hybrid microwave refers to the microwave that transmits native E1 services and native Ethernet

services in hybrid mode. The Hybrid microwave supports the AM function. During the transmission, the

Hybrid microwave does not change the features of the E1 services and Ethernet services.

• The RTN 900 V1R2 has a built-in MADM and a packet processing platform. The MADM transmits E1

services that are accessed locally or extracted from the SDH to the microwave port. After processing the

accessed Ethernet services in the unified manner, the packet processing platform transmits the Ethernet

services to the microwave port. The microwave port maps the E1 services and the Ethernet services into

Hybrid microwave frames and then transmits the Hybrid microwave frames.

• Ericsson proprietary protocol used to carry Ethernet traffic on radio link

Modulation Modes

• The TDM microwave only supports fixed modulation. The Hybrid microwave supports fixed modulation and adaptive modulation (AM). – The fixed modulation refers to a modulation scheme wherein a modulation scheme is adopted

invariably when the radio link is running. When the fixed modulation is adopted, the modulation scheme can be configured through software. A modulation scheme can range from QPSK to 256QAM.

– The AM is a technology through which the modulation scheme can be adjusted automatically according to the channel quality. When the AM is adopted, the lowest modulation mode (also called reference mode) and highest modulation scheme (also called nominal mode) can be configured through software.

Capacity

Time99.999%

Voice

Adaptive Modulation

Outage: 5.25min

99.998%

99.995%

99.99%

99.95%

256QAM128QAM

64QAM 64QAM128QAM 256QAM

32QAM99.9%

Outage: 10.51min

Outage: 26.28min

Outage: 52.56min

Outage: 262.80min

Outage: 525.60min

QPSK

16QAM

Packet radioGSM

HSPA

Time

Capacity

99.999%

Fixed Modulation

Fixed Bandwidth

TDM radio

QPSK

Outage: 5.25min

GSM

HSPA

AM Technology Through the AM technology, the Hybrid microwave uses a high-efficiency modulation scheme when the

channel is of better quality. Hence, more user services can be transmitted and thus the transmission efficiency and spectrum utilization are improved. When the quality of the channel is degraded, the Hybrid microwave uses the low-efficiency modulation scheme, in which only the services of a high priority are transmitted. Hence, the anti-interference capability of links is enhanced and availability of the links on which the high-priority services are transmitted is ensured.

E1 services are of the highest priority in the AM-based Hybrid microwave transmission. Ethernet services are classified into flows of different priorities based on the CoS technology. When the Hybrid microwave uses the lowest-efficiency modulation scheme, the equipment transmits E1 services only (if the service bandwidth is higher than the total bandwidth of the E1 services, the Ethernet services of a high priority can be transmitted). When the Hybrid microwave uses other modulation schemes, the increased bandwidth can be used to transmit Ethernet services. In this case, availability of the links on which the E1 services and Ethernet services of a high priority are transmitted can be ensured and the capacity for transmitting Ethernet services increases.

AM Features

Detected SNR

decreased

Prepare to Switch to 32QAM

Detected SNR

Increased64QAM 32QAM Massage32QAM 64QAM Message

Prepare to Switch to 64QAM

The AM technology can use the QPSK, 16QAM, 32QAM, 64QAM, 128QAM, and 256QAM modulation schemes. The lowest modulation scheme (also called reference mode) and highest modulation scheme (also called nominal mode)

can be configured. When the modulation schemes of the AM are switched, the transmit frequency, receive frequency, and channel spacing

do not change. When the AM modulation scheme is switched, the step by step mode is adopted. When the AM switches the modulation scheme, the services with a low priority are discarded but no bit errors or slips

occur in the services with a high priority. The speed of switching the modulation scheme meets the requirement for no bit error in the case of 100 dB/s fast fading.

Modulation Bandwidth Capacity

32QAM 28MHz 100 M

64QAM 28MHz 150 M

AM—Increasing the Bandwidth by Four Times

EOS Packet

Band 7G 7G

Distance 30.6 km 30.6 km

Bandwidth 28 Mbit/s 28 Mbit/sModulation

schemeQPSK 128QAM

Transmission capacity

40 Mbit/s 200 Mbit/s

Important feature of the packet microwave: The modulation scheme can be automatically changed according to the transmission conditions of the air interface, thus ensuring high-level service transmission.

Increasing the bandwidth by four times on sunny days: Under the same conditions, the OptiX RTN equipment can support the 200 Mbit/s capacity but the EOS of the TMD can support only the 40 Mbit/s capacity.

Eight QoS levels on rainy days: The monitoring mechanism ensures the fine and hierarchical service transmission.

Encapsulation

AM

Element in Network

Planning

Voice

Data

VoiceData

VoiceData

Real-time service

Non-real-time service

256QAM

128QAM

64QAM

16QAM

32QAM

QPSK

Modulation scheme

99.999%

99.9%

99.99%

Ethernet over PDHThis section describes Ethernet over PDH, including HW configurationexamples and required HW.

Required HW Requires a LicenseNPU3, NPU3 B, NPU1 B, or NPU1 CMMU2 B/C/D/H No

The Ethernet traffic is transported between NEs in multiple E1s, over a singlehop, or through a network. Figure 16 shows an example of how the differentunits can be used in a network.

Cards supporting Ethernet functionality

• ETHERNET INTERFACE UNIT(ETU)• NODE PROCESSOR UNIT(NPU)• MODEM UNIT(MMU)