The emergence of small cells and new shared spectrum options, such as Citizen’s Band Radio Services (CBRS), have paved the way for a new network architectural model that delivers mobile network operator (MNO) network coverage and capacity across private LTE/5G RANs in locations that are deemed to have weak signal strength.

This model is known as a neutral host network (NHN). It involves a third-party wholesale carrier offering its network to be transmitted and accessed from a certified private LTE/5G network. Basically, one private LTE/5G network deployed in shared spectrum such as CBRS provides service to mobile subscribers from multiple MNOs – essentially extending the service to public cellular service.

The role of an NHN is to leverage existing private LAN, WAN and RAN network infrastructure to propagate MNO carrier signals. This architecture can create enhanced signal strength or capacity in locations where signal strength is low or at certain venues where it doesn’t make sense for each MNO to deploy and manage a separately owned RAN.

Neutral host networking is a relatively new concept that, unlike traditional models, allows multiple parties - both private and public - to securely share the same network infrastructure within an organization. Doing so provides wireless connectivity to a wide range of MNO subscribers with the goals of increasing public cellular network coverage and capacity while dramatically reducing capital and operating expenses using a shared network infrastructure approach.

For users of the network, an NHN operates seamlessly with their MNO’s regular cellular network and will be entirely transparent to them. Accessing the NHN doesn't take any user input or action to roam into and out of the network with minimal interruption of service.

NHNs are an ideal choice for extending the coverage of existing mobile networks, especially where coverage is limited or non-existent, such as inside a building (coverage extension). MNO’s can also offload capacity in areas where networks are congested with too many users or high data traffic loads (capacity augmentation) in a scalable manner.

Celona Neutral Host works with T-Mobile’s Build Your Own Coverage (BYOC 2.0) program, providing in-building coverage solution to Enterprises. We are working with other major US carriers to offer in-building coverage in the future.

The cost and complexity of extending cellular services indoors is the main driver for neutral host networks.

Poor cellular coverage and low throughput inside buildings and large venues has driven organizations to deploy extremely expensive and complex distributed antenna systems (DAS) that amplify cellular carrier signals over a passive cabling run throughout a given site. This disparate and discrete system requires specialized cabling, RF antennas and carrier infrastructure equipment to process signals, terminate and route connections.

The neutral host model is a new approach that radically reduces this cost and complexity by allowing small cell access points operating in the CBRS spectrum to be deployed and connected over an existing enterprise local area network (LAN) environment with carrier traffic automatically offloaded and securely tunnelled over broadband or Internet connections to the respective mobile network operator (MNO).

Most smartphones and LTE devices manufactured in the last three years are natively compatible with networks that operate in the 3550 to 3700 MHz CBRS frequency range. Not only can this frequency spectrum be used for private mobile network purposes, but a defined portion of the available bandwidth can also be used to advertise public MNO networks. This means that any CBRS-capable device with a public carrier SIM that’s being advertised on the CBRS spectrum can connect and use the MNO network services natively as if it were connected to a public MNO cell tower.

With a full ownership of integrated Core and RAN networks, including frequency spectrum via the CBRS band, an NHN operator essentially becomes the network operator of indoor venues.

NHNs may be managed by a third-party managed services provider (MSP) or the enterprise organizations themselves. This enables private mobile network devices and public mobile network operator (MNO) subscribers involved to maintain connectivity and ensure network coverage.

The MNO is fully in control of their own wireless services as core network functions and services like IMS are derived and managed from the MNO’s existing network securely accessing through an IPsec tunnel that interconnects the MNO network with the private LTE/5G network. Also note that NHN provides all the critical KPIs to MNOs. By leveraging the CBRS band as a common shared spectrum for indoor access, a portion of the RAN bandwidth can be allocated for MNO use. This eliminates the need to use separate infrastructure equipment to propagate licensed MNO spectrum.

Despite the significant enhancements with LTE, good and reliable indoor coverage has eluded many enterprises. This is primarily due to poor RF signal penetration inside large buildings using carrier macro cells deployed outdoors and often far away. This problem gets even worse with new energy efficient buildings with low-E glasses etc.

There is growing need for a neutral host network that can be directly owned and operated by enterprise organizations to bridge the gap between very large projects with direct MNO involvement and large numbers of smaller projects that are too small for carriers to consider, but also too complex for enterprises to handle on their own. This has created the need for a low-cost solution that removes complex and costly implementation models associated with multi-operator support.

As a result, NHNs offer a myriad of benefits to enterprises, MNOs and subscribers alike. These include but are not limited to:

The fundamental concept of a neutral host is the sharing of deployed network infrastructure components. Network sharing is enabled through methods such as sharing the campus, tower, rooftop, power, cabinets, lighting, and air conditioning. Active sharing of the network involves dynamic real time sharing of antennas, access networks, transmission, spectrum, RF design, planning, and core network functions.

Neutral host networks add the ability to easily integrate CBRS cellular access points to an existing network infrastructure to broadcast multiple signatures of different private and MNO networks, securely tunneling traffic directly to each requisite network operator ‘s mobile core.

Roaming onto a Neutral Host Network (NHN) leverages the same cellular roaming principles and procedures as roaming onto another RF band of a given operator’s network.

A user device first discovers a NHN by automatically scanning the CBRS frequency band for a network broadcasting one or more network identifiers. The device reads the list of public land mobile network (PLMN) IDs from the broadcasted signature. (Note: If the mobile network operator has a commercial roaming agreement with the NHN operator, then the NHN would be broadcasting the participating MNO’s network identifier PLMN-ID.)

The device is provisioned with the PLMN information of the participating SP. Once this device attaches to the NHN, it is authenticated by the MNO’s core network with the provisioned SIM credentials.

Once a user device roams onto an NHN, the data connection subscribed to the device is supported on the secure tunnel established between NHN and MNO.

Celona provides all the necessary network components (RAN, core network, Orchestration) required to enable NHNs leveraging the existing enterprise network infrastructures within a fully integrated, simple to deploy solution architecture. They include:
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Celona Access Points:

These are small form-factor base stations or access points, that operate within the 3.55 to 3.7 GHz band (also known as the Citizens Broadband Radio Service or CBRS) supported by 4G LTE and 5G standard. These small cells provide Neutral Host (NH) shared RAN access for participating MNOs UE devices at select indoor venues where Celona Neutral Host service is enabled
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Celona Edge:

Scalable and resilient cloud-native network operating system built for Enterprise deployments. It delivers converged 4G/5G core services, intelligent spectrum management and a full-function IP stack for seamless connectivity into enterprise LANs

Celona Multi Operator Exchange (MOXN)

A cloud-based multi-operator exchange built to meet the highest levels of scalability and security requirements of Enterprises and MNOs. It establishes a secure tunnel between the Celona 5G LAN and the MNO(s) core and provides critical functions to operate Neutral Host service efficiently and securely

Orchestration and management:

A unified cloud-based network orchestration and management platform for both Private Wireless and Neutral Host services that delivers complete visibility and control over your network, devices, and traffic flows - including zero touch installation of Celona APs, and Edge OS, and visibility into usage and performance of the Neutral Host service

None. The only requirements are that the organization currently has an operational Celona private cellular infrastructure in place and a LAN and internet infrastructure with sufficient bandwidth to support Cellular RAN traffic traversing it.

Yes, MNO subscriber devices with MNO provided SIM, can roam seamlessly between MNO network and the private LTE/5G networks that support NHN operation.

Yes, user devices must support the CBRS band 48. There is now a large ecosystem of CBRS-supported devices and most new smartphones and SIM-capable tablets come with native CBRS compatibility.

While neutral host networks are a viable new option for “greenfield” deployments where there is no existing distributed antenna system (DAS) in place – or the existing DAS is end-of-life, they can also be designed and deployed to complement existing DAS environments by providing additional cellular capacity and coverage using the CBRS band and the existing enterprise network infrastructure to connect to MNO networks.

This strictly depends on the different certifications that each 5G RAN equipment vendor has with particular MNOs. Celona has completed certification with T-Mobile in the US (T-Mobile BYOC 2.0) and T-Mobile service on Celona Neutral Host solution is commercially available. Celona is also engaged in the certification process with several of the top MNOs in the US.

The 3GPP standard allows for up to 6 network identifiers to be broadcasted on the NHN including private 5G LAN services. With private network operations, it allows for up to 5 MNO’s to be supported on the NHN. Otherwise, up to 6 MNO’s can be simultaneously supported.

Celona Neutral Host is offered as a Managed Service, hence Celona will interface with the MNO to

The only requirement on the Enterprise from MNO perspective is to sign a retransmission agreement with T-Mobile before Celona order is placed

Celona Neutral Host is offered as a Managed Service, and hence Celona is responsible for managing network performance and experience as per MNO SLA requirements. Celona Customer Success will proactively monitor the network and any degradation in Neutral Host related KPIs will trigger a troubleshooting workflow to determine if the issue is on the Enterprise segment (LAN, WAN, Celona AP/Edge) of the network or within the MNO’s core network. Based on the triaging one of Enterprise IT, Celona Support or MNO’s network team will be engaged to address the issue.

When a private LTE/5G network is first designed, architects take into account the total throughput capacity of the new radio network and ensure that this throughput can be supported by the existing LAN and WAN infrastructure. If not, upgrades will need to be made to support the added throughput capacity. Bandwidth calculations for all traffic sent between the private 5G LAN and MNO(s) across the established secure tunnel(s) will need to be calculated and maximum internet throughputs adjusted to handle the additional traffic load.

Celona architecture addresses data security and segmentation concerns associated with the sensitive subscriber data traversing a corporate LAN by logically segregating private network traffic from public MNO traffic. The following diagram shows how separate secure tunnel is established at each Celona Access Point (AP) to transport data destined to one or more remote MNO networks. Once the MNO traffic reaches the MOCN gateway, traffic from the single MNO tunnel is segmented onto individual secure tunnels and transmitted to the MNO’s core network services.

No. The experience is effectively identical. This includes MNO location/emergency services (e911calling, Wireless Emergency Alerts (WEA), and Wireless Priority Services (WPS)) . Emergency services do not function when using Wi-Fi calling.

No. The end user will not experience any difference when connecting to MNO’s using an NHN over CBRS frequencies compared to natively connecting to MNO bands that are distributed via a DAS.

It depends on the cellular band being used. However, the design phase of a private 5G LAN rollout will account for the frequency penetration of CBRS band 48 which will ensure that access point placement and signal strength will be adjusted appropriately so that complete coverage in buildings/campuses is achieved.

Celona’s Neutral Host offering is targeted at Enterprises that have not been well served by traditional solutions, like carrier DAS, to address lack of in-building public cellular coverage.

Celona Neutral Host is a turn-key solution uniquely engineered for the enterprise to address the challenge of fast and reliable in-building public cellular coverage. Celona’s cloud-first, fully integrated Neutral Host solution has been architected with cost-savings, deployment simplicity and ease-of-management in mind. Additionally, Celona multi-purpose design enables enterprises to securely use both private and multiple public networks services on the same shared infrastructure dramatically reducing capital and operating expenses.

Here is a summary of some of the key features and benefits to Enterprises –

Celona Neutral Host is offered as a 3 or 5 year per AP Neutral Host subscription. Subscription includes all the software, hardware and managed services required to design, deploy and operate a Neutral Host network -

Pricing has been structured to offer flexibility for the customers to select “a la carte” subscription option that best fits their use case, to ensure that they only pay for the required products / services. Neutral Host subscription price will be calculated based on the following parameters:

Neutral Host pricing model also provides flexibility to co-term additional services to an existing subscription at a later point, making entire ordering process seamless and stress free.

Federated Wireless and InfiniG are System Integrators using product components from multiple vendors and putting together a “Frankenstein” solution, suited for Telecom Operator consumption. Operational complexity & associated cost makes this solution untenable for Enterprises.

Celona’s Turnkey product, from radio to core to cloud management, has been architected to work together as a complete ecosystem rather than components that need integration.

Celona is working closely with additional Tier 1 operators in the US to go through product certification. We expect to add second operator to the offering in Q2 ’24. Customer will be able to turn on the additional operator service on their existing Neutral Host network with an incremental add-on subscription without requiring any additional hardware.

Celona Neutral Host is offered as a Managed Service, and hence Celona is responsible for managing network performance and experience as per MNO SLA requirements. This includes engaging with the operator for

Customers will be able to use the Orchestrator to track the overall health and activity of the Neutral Host service. Additionally detailed KPIs and Alerts for Neutral have been added for MNO consumption. This is available to Enterprises programmatically via APIs.

Celona Neutral Host is expected to open up new target segments amongst “Carpeted” Enterprises, namely –

Amongst Celona’s existing customers and target verticals (“Uncarpeted” segment), we expect interest amongst –

While neutral host networks are a viable new option for “greenfield” deployments where there is no existing distributed antenna system (DAS) in place – or the existing DAS is end-of-life, they can also be designed and deployed to complement existing DAS environments by providing additional cellular capacity and coverage using the CBRS band and the existing enterprise network infrastructure to connect to MNO networks.

Celona Neutral Host solution has gone through a thorough validation before being certified by T-Mobile. We have had a fully operational end-to-end solution with T-Mobile and a National retailer for over 6-months. This level of scrutiny is required by the MNO as part of the certification because post-certification Celona Neutral Host will be a extension of the MNO network and will be delivering public cellular services to MNO subscribers. Any degradation in performance and user-experience will be attributed to the MNO by the subscriber. To ensure highest levels of performance and user-experience, MNO will be involved in the following –

We anticipate that other MNOs will follow a similar engagement model for certification and post-certificate operations.

As part of the certification, T-Mobile has validated and approved not just Celona Multi-operator Exchange (MOXN) architecture and functionality but also Celona’s Cloud Management and Security practices. Having each enterprise go through this process is untenable and hence Celona MOXN will only be available as a cloud service from Celona.

QoS is guaranteed on Celona 5G LAN for both Private and Public subscriber traffic using 3GPP compliant QoS Class Identifier (QCI). For MNO traffic this is set by the MNO core, while for Private network traffic Enterprises can define appropriate policies for devices using MicroSlicing.