Uninterrupted train-to-trackside communications

One of the major concerns of rail operators is to establish a high-speed, reliable and continuous communication between a train in motion and the trackside for a smooth CBTC operation and also to collect data from CCTV, maintenance, VoIP, PIS, etc. and retrieve real-time information of these data streams.

> THESE APPLICATIONS REQUIRE HIGHLY-AVAILABLE NETWORKS.

The latest ACKSYS products combining WiFi 802.11ax (WiFi 6) and 5G cellular connectivity enable seamless communication with uninterrupted data flow between on-board equipment and the ground.

For subways and tramways, train-to-ground communication generally uses WiFi with access points on the ground (AP mode) and on-board (client mode).

The solution’s redundancy is ensured by 2 ACKSYS RailBox access points installed on board, one at the front of the train and the other at the rear, using the VRRP protocol.

The distance between each ground AP is determined by the speed of the subway, the throughput required and the level of redundancy required. For the ground infrastructure, ACKSYS offers 2 solutions:

  • RailTrack (triple WiFi radio, 100-240 VAC power supply, SFP ports and 1Gbps Ethernet connectors in M12 format)
  • RailBox (dual WiFi radio, 24-110 VDC or PoE power supply, 2.5Gbps Ethernet connectors in M12 format)

ACKSYS has developed a high-performance solution for on-board ground communication: CBB (Connect Before Break).

With a roaming time close to 0ms and a packet loss of less than 0.1%, data rates are very high and communication quality is very good. This solution requires on-board ACKSYS APs (client mode), and can work with ACKSYS ground APs or those from other manufacturers.”

Cellular communications are also increasingly used for the transmission of non-critical information such as video surveillance and passenger information, using private or public networks. Streams from several mobile networks can also be aggregated to provide an optimal connection. ACKSYS cellular RailBox are deployed in both 4G and 5G on numerous train-to-ground communication projects.

 

 

  

GIGABIT BASED MOBILITY SUITE FOR
TRAIN-TO-WAYSIDE COMMUNICATIONS
 
 

 

APPLICATION HIGHLIGHTS
 

> MULTIPLE REDUNDANT MECHANISMS
– Redundant train-to-ground communication, automatic assignment of front or rear radio (VRRP)
– Dual radio APs for trackside
– Hardware redundancy (wireless, Ethernet, power supply)

> 500 MBPS DATA THROUGHPUT AT 350 KM/H
– Connect before break technology
– Packet error rate (PER) < 0.1%

> ROAMING LATENCY < 30 ms
– Dualband, limitless channels
– Highly versatile roaming algorithm able to handle two-way traffic of a train
– IEEE802.11r fast transition protocol
– WiFi pre-authentication, OKC …

> DIRECT CONNECTION TO TRAIN POWER SUPPLY
– 24-110 VDC insulated dual input power supply

  

> NETWORK EFFICIENCY AND SAFETY
– Supports VLANs and tunnels
– Security : radius authentication

> EASY MAINTENANCE
– Configuration stored on a removable key

> RAILWAY HARDENED
– IP66
– Radio : WiFi : EN 300 328 (2.4 GHz), EN 301 893 (5 GHz, DFS) /
LTE : EN 301 908 [-1, -2, -13], EN 301 511, EN 303 413
– EMC : WiFi : EN 301 489 [-1], [-17] / LTE : EN 301 489 [-19], [-52] /
Railway : EN 50155, EN 50121-3.2
– Safety : EN45545-2 (HL3), NF F16-101 (M1F1) (Fire and Smoke), EN60950-1, EN62311
– Environmental : EN61373 (shock & vibration), EN60068 (climatic)

  

 

Railway WiFi access points & cellular routers

 

 

RailTrack
  RailBox RuggedAir RailTrack

Function

Cellular router or dual-radio WiFi access point

WiFi access point, client, repeater

WiFi access point & backbone repeater
Recommended for

GROUND INFRASTRUCTURES & ONBOARD

ONBOARD

TRACKSIDE & TUNNEL INFRASTRUCTURES

WiFi interface

Single or dual radio
WiFi 5: 2.4 / 5 GHz
WiFi 6: 2.4 / 5 GHz
WiFi 6E: 6 GHz
Mu-MIMO 4T4R

Single radio
WiFi 5
2.4 / 5 GHz

Triple radio
WiFi 4 and WiFi 5
2.4 / 5 GHz
Cellular interface

Dual SIM
4G LTE / 5G*
GNSS multi-constellation

 

–

 

–

Maximum number of clients simultaneously connected in AP mode

512 per radio (number of clients recommended for an optimal WiFi experience : 120 per radio)

125 per radio (number of clients recommended for an optimal WiFi experience : 40 per radio)

N/A
TECHNICAL CHARACTERISTICS

Ethernet interface

2 x 2.5 Gbps
M12

2 x 1 Gbps
M12

2 x 1 Gbps (M12)
2 x optical fiber (SFP cage)
PoE+ PSE injector

I/O

1 isolated input
1 isolated output

Dimensions (mm)

80 x 175 x 57

80 x 175 x 57

305 x 200 x 75

Power supply

Redundant – Isolated
24 to 110 VDC – PoE +

Redundant – Isolated
9 to 48 VDC – PoE

Isolated
110 to 230 VAC (50 / 60 Hz)

Environment
Operating temperature
IP rating

Extended : -40°C to +70°C, +85°C for 10 mn

EN 50155 / EN 45545-2 / EN 61373 / EN 60068
IP66
FUNCTIONALITIES

Roaming

0 ms

< 30 ms

N/A

Mesh (802.11s)

YES

YES

YES

Security

Firewall, https, MAC filtering, WPA2/WPA3-Personal & Enterprise (IEEE 802.1X/RADIUS), DoS, L2 tunnels (GRE), VPN (OpenVPN, IPsec), SNMP V3, WIDS, Rogue AP detection

Ethernet networking

Frame filtering, bridge, repeater, STP/RSTP, VLAN, WMM QoS, DHCP (server and client), DNS relay

Ethernet routing

Multicast (PIM), IP redundancy (VRRP), static routes, NAT router, router

Carriage coupling system SRCC

YES

YES

N/A

Administration

http, https, SNMP agent (V1, V2C, V3), WaveManager administration software

Bypass relay option
 (Daisy Chain Ethernet topologies)

YES

NO

YES
C-Key** YES YES YES

    *Optional 2nd radio interface (WiFi or cellular)   **Hardened memory key (configuration backup)