Ouroboros Telecom
2G / 3G / 4G / 5G

When a flood, a fire or an industrial accident threatens a town, the authorities need to reach every phone in the area within minutes, without a subscriber list and without saturating the SMS core. Cell broadcast does exactly that. The Ouroboros CBC sends the message once to the radio network, and every handset in the selected cells receives it, on 2G, 3G, 4G and 5G.

AMTP · CBC / CBCF
FunctionCell Broadcast Centre, CBCF in 5G (SMS-CB and public warning)
InterfacesCBSP (BSC) · SABP / Iu-BC (RNC) · SBc-AP (MME) · N50 (AMF)
ConsoleMap-driven CBE with selectable zones
MessagesText (GSM 7-bit, UCS-2) or binary, single or multiple
SchedulingStart, end and repetition interval per message
DeploymentVMware, KVM, Docker, Kubernetes
300 000
cells per broadcast minute on two 1U servers
2G · 3G · 4G · 5G
one centre for every radio generation
99.999%
availability
No limit
on cells or groups of cells
00The problem

An SMS campaign needs a list of numbers, and it queues behind every other message on the SMS core. In an emergency, the people in danger include roamers and visitors whose numbers nobody has, and the minutes lost while the SMSC works through millions of messages are the minutes that matter.

Cell broadcast solves both problems: one message per cell, received by every handset camped on it. But the radio network is rarely uniform. BSCs, RNCs, MMEs and AMFs from different generations and manufacturers each expect their own protocol, and a warning that reaches only one layer misses everyone camped on the others.

01How it works

CBC / CBCFcore
BSCCBSP, 2G cells
RNCSABP over Iu-BC, 3G cells
MMESBc-AP, 4G eNodeBs
AMFN50, 5G gNodeBs
01 / 03

Define the message and the zone

Authorities and the operator define the warning in the Cell Broadcast Entity (CBE), a graphical console. The target zone is drawn on a map from cells, named groups such as a town or a district, or several selectable zones. Each message carries its text or binary content, its start time, its end time, its repetition interval, the broadcast channel and the emergency indication that separates a warning from a normal broadcast.

02 / 03

The CBC resolves the cells

The CBC holds the position, shape and radius of every cell and groups them by BSC, RNC, MME or AMF. It determines the set of cells for each message, allocates the serial numbers that tell handsets which broadcasts they have already shown, and indicates the geographical scope of the message.

03 / 03

Broadcast on 2G, 3G, 4G and 5G

The message goes to the BSCs over CBSP, to the RNCs over SABP on the Iu-BC interface, and to the MMEs over SBc-AP, which relay it to their eNodeBs. In the 5G core, the CBC acts as Cell Broadcast Centre Function (CBCF): it sends the warning to the AMFs over N50, a service-based interface on HTTP/2, and the AMFs relay it to their gNodeBs. Messages held by the radio controllers can be replaced, modified or deleted at any time, and the CBC queries their status and load.

Reference architecture
Radial architecture diagram of the Ouroboros Cell Broadcast Centre. Authorities and the operator define the messages and the target zone in the CBE graphical interface; cells and radio controllers are provisioned by CSV file. The CBC broadcasts each message to the 2G BSCs over CBSP, to the 3G RNCs over SABP on the Iu-BC interface, and to the 4G MMEs over SBc-AP, which relay it to the eNodeBs; as Cell Broadcast Centre Function (CBCF) it sends it to the 5G AMFs over N50, which relay it to the gNodeBs.

CBC / CBCF — public warning to every cell of a zone, on 2G, 3G, 4G and 5G

02Use cases

Public warning, emergency alerts, area information, network announcements — one broadcast centre.

01

Public warning of the population

Natural disasters, industrial accidents and public safety threats are announced to every handset in the affected area, including roamers and visitors, without any subscriber list.

02

Emergency messages on every generation

The same warning reaches 2G, 3G, 4G and 5G cells at once, with the emergency indication that handsets present differently from a normal broadcast.

03

Information by area

A town, a district, an event site or a border zone receives its own message, defined on the map and repeated for as long as it is needed.

04

Network and commercial information

Cell or area names, service announcements and local offers are broadcast to the subscribers present in a zone, without loading the SMS core.

Legos

We've selected Ouroboros because it was the best company capable of fulfilling our need for a scalable and virtualised full MVNO platform. Moreover, the Ouroboros team is pragmatic, flexible and responsive.

Pascal Prot

CEO-CTO · Legos

03Specifications

Function
Cell Broadcast Centre (SMS-CB, public warning); Cell Broadcast Centre Function (CBCF) in 5G
Interfaces
CBSP (BSC), SABP over Iu-BC (RNC), SBc-AP (MME), N50 (AMF)
Protocols
CBSP, SABP, SBc-AP, SCTP, TCP, HTTP/2 (Namf Communication)
Console
Graphical CBE with map, selectable zones, groups and messages in emission
Cell management
Position, shape and radius; groups per BSC, RNC, MME or AMF; named groups
Messages
Single or multiple; GSM 7-bit, UCS-2 or binary
Message control
Write, replace, modify, delete; status and load queries
Scheduling
Start time, end time, repetition interval, broadcast channel, emergency indication
Provisioning
Cells and radio controllers by CSV file
Capacity
One message per minute to 300 000 cells on two 1U servers
Redundancy
2 or 3 instances in parallel; geographic redundancy
IP support
IPv4, IPv6
Virtualisation
VMware, KVM, Docker, Kubernetes
Cloud
AWS, Azure
Hardware
Bare metal COTS
Standards
3GPP compliant
Availability
99.999%
Business model
OPEX rental · CAPEX licence
04Inside the platform

01

One centre for 2G, 3G, 4G and 5G

CBSP, SABP, SBc-AP and N50 from a single CBC, with the manufacturer variants of the BSCs, RNCs and MMEs. No separate broadcast platform per generation.

02

Map-driven zone selection

Cells carry their position, shape and radius. Operators select the target on a map, by named group or by several zones at once.

03

No limit on cells or groups

The cell and group tables have no fixed ceiling. A national network and a single campus run on the same product.

04

Full message life cycle

Single or multiple messages, in text or binary, are scheduled with a start, an end and a repetition interval, then replaced, modified or deleted on the radio controllers when the situation changes.

05

Status and load of the radio network

The CBC queries the messages in emission and the load of the radio controllers, so the operator knows what is being broadcast and where.

06

Simple provisioning

Cells, BSCs, RNCs, MMEs and AMFs are loaded from CSV files exported from the radio planning tools.

07

IPv4, IPv6 and dual-stack

Every interface runs over IPv4, IPv6 or both. The element fits an IPv6 core or a mixed network without a separate configuration.

05Why Ouroboros

A public warning system is only as good as its weakest radio layer. The Ouroboros CBC covers 2G, 3G, 4G and 5G from one console, so a warning issued once reaches every handset in the zone, whatever network it is camped on.

The product is sized for national use: two 1U servers broadcast one message per minute to 300 000 cells, and two or three instances can run in parallel for the service. It runs on bare metal, VMware, KVM, Docker or Kubernetes, alongside the rest of the Ouroboros core or in front of any vendor's radio network.

Ouroboros Telecom

Tell us your radio vendors, the number of cells, and the authorities you work with. We'll show how the CBC covers 2G, 3G, 4G and 5G from one console.