Private Wireless Network Types & Technical Needs

Limitless Mobile has been actively designing, deploying and managing Private Wireless Networks (PWN) for several years now and our team’s past experience in PWN’s actually goes back almost 20 years outside the US.

As more and more companies in the US are evaluating the value of deploying a PWN, understanding the types of PWNs and their respective technical requirements might be helpful.

We identify four types of PWNs today based on their functionality and technical needs. I published the first overview of the types a few years ago, but here’s an update on the descriptions:

1)???Closed Network for Data-Only Devices

The simplest type of PWN technically is a closed, island-type network for data-only devices (e.g. IoT devices, tablets, etc.) such as a factory or a warehouse.

Closed refers to the fact that the devices on the network do not need to leave the network nor be able to communicate with other data-only devices outside the network, but all communication is restricted to within the PWN.

If a company deploys multiple island-type PWN’s, e.g. multiple factories, allowing the devices to be deployed on any one of them, the type of PWN is still closed as the technical capabilities remain the same.

To manage the devices from a core network, International Mobile Subscriber Identities (IMSI), which are typically derived from a Public Land Mobile Network (PLMN) code, are needed. However, due to this being a completely closed network without a need for the devices to interact with outside the network, a “notional” block of IMSI’s could be created and used instead of formally assigned IMSI resources.

From a wireless core network perspective, only simple functionality is needed, so a core-network-in-a-box type solution is the most logical option due to cost as well as ease of deployment and management.

Similar approach to the Radio Access Network (RAN) makes sense i.e. while 3GPP compliant solutions should be preferred, e.g. a Tier 2 or Tier 3 Network Equipment Provider (NEP) should be sufficient for most use cases.

Depending on the size of the RAN, the network can be monitored and managed in-house or if it’s bigger or otherwise strategically logical, monitoring and management can be outsourced to a specialist wireless NOC-as-a-service provider.

2)???Closed Network with Support for Outside Interaction

Expanding from data-only devices to smartphones on a closed network adds a significant layer of complexity to the PWN. The first big driver for complexity is the need to ?

support voice, which triggers regulatory requirements and adds new requirements for the core network. The second is a need for the devices on the network to be able to interact outside the PWN.

Examples of closed networks requiring support for outside interaction include e.g. private planes, yachts, ships, government facilities (e.g. secure office buildings) etc.

The addition of voice and SMS as hence, the need to make devices discoverable to enable communication to and from outside the PWN, translates to a need for using IMSI’s based on a publicly recognised PLMN based (i.e. notional ones no longer suffice) as well as using Mobile Station International Subscriber Directory Numbers (MSISDN).

The PWN also needs to register and connect with the Local Access and Transport Area (LATA) and secure a Local Routing Number (LRN) to enable routing of voice calls to and from the devices on the PWN.

Addition of voice also means a need to comply with regulatory requirements (e.g. Public Safety Answering Point (PSAP) support for emergency calls (i.e. E911) and Lawful Intercept (LI), need to pay Universal Service Fees (USF), make regular filings, etc.).

To enable two-way Short Message Service (SMS) functionality, the PWN needs to deploy an SMSC as well as connect and integrate with an SMS Inter-Carrier Gateway.

From a core network perspective, the addition of voice, which means either Voice over LTE (VoLTE) for 4G or Voice over New Radio (VoNR) for 5G, translates to a need for an IP Multimedia Subsystem (IMS) core network.

This represents a significant increase in functionality from the core network and means that most core-network-in-a-box solutions are no longer options on their own and the PWN needs to focus on carrier-grade solutions from Tier 1 vendors, which means the cost of the required core network grows substantially.

To ensure that the RAN supports voice, many NEP’s require additional licensing, but e.g. the eNodeB (for LTE) or gNodeB (for 5G) hardware remains the same as for serving data-only devices.

While the complexity of communications, due to need to support voice and interaction outside the PWN, increases, network monitoring and management can still be handled either in-house or outsourced depending on preference of the PWN.

3)???Closed Network with Outbound Roaming

A growing number of companies are realising that their PWN needs an outbound roaming capability i.e. the data-only devices or smartphones using the PWN should be able to roam outside the PWN e.g. on a nationwide wireless carrier, but not allowing devices from the public wireless carrier to roam onto the PWN.

The need can be driven by a variety of reasons such as use case need (e.g. PWN devices frequently leave the PWN RAN coverage), coverage (i.e. cheaper to roam than operate a RAN), redundancy or capacity (i.e. providing extra capacity for usage peaks) reasons.

Adding outbound roaming doesn’t impact the technical requirements for the PWN RAN, apart from a need for handover testing with the neighbouring wireless carriers.

However, more functionality is required from the core network (e.g. a Diameter Routing Agent (DRA) for LTE or Security Edge Protection Proxy (SEPP) for 5G).

Further, the numbering assets used now need to be tied to an IR.21 (i.e. a roaming information document used by wireless carriers), supported by roaming agreements, which means a requirement to be able to negotiate them and perform International Roaming Expert Group (IREG) testing.

To support roaming interactions with public wireless networks, the PWN needs access to IP Packet eXchange (IPX) as well as have access to Data Clearing House (DCH) and Financial Clearing House (FCH) services.

Alternatively, the company could look to avoid the cost for external DCH and FCH services by handling these functions in-house. This would require ability to generate industry standard i.e. Transferred Account Procedure (TAP) based roaming billing records in-house. However, this is not typical today.

From a network monitoring and management perspective, the addition of roaming ability for the devices / subscribers outside the PWN now increases complexity of the monitoring and management task due to e.g. need to be able to monitor device / subscriber behaviour while roaming.

Due to the complexity and cost of the infrastructure, specialist expertise and experience as well as external services required, most companies looking to add roaming to their PWN choose to understandably partner with a specialist company providing them with roaming-as-a-service.

4)???Open Network

The last type is an open PWN i.e. one that allows users from e.g. nationwide wireless carriers to inbound roam onto the PWN.

Examples of such networks include e.g. sports venues, school / college / university campuses, malls, and public smart city locations (e.g. government facilities).

To support inbound roaming requires the PWN to broadcast a wireless carrier identity, which is recognised by the wireless carrier community and supported by both an IR.21 and inbound roaming agreements.

In short, the technical requirements are identical to the previous type – apart from broadcasting a recognise wireless carrier identity and needing to manage inbound roaming billing processes.

To support inbound roaming, in addition to needing to have roaming agreements in place to support this, the PWN would be required to support TAP billing as wireless carriers who would be inbound roaming onto the PWN would expect TAP billing records to be provided.

The requirements for the RAN do not chance technically, although testing and aligning handovers with neighbouring wireless carrier networks now becomes a more critical activity to ensure desired roaming behaviour.

The monitoring and management of the network continues to increase in complexity as roaming partners that might have devices / users inbound roaming onto the PWN will expect ability to identify and resolve issues quickly.

These four network types cover PWN’s, which Limitless Mobile has come across to date. It should be noted that there are variations of the types such as Open Network for example for a government facility, which is “open” theoretically, but access is restricted by the PWN to only selected users from public wireless carriers.

The last important takeaway is to recognise that the PWN types are described to highlight technical requirements, which does not mean that everything needs to be dedicated or operated in-house.

On the contrary, as the technical requirements expand, partnering with a specialist company to leverage as-a-service propositions to reduce risks, CAPEX, OPEX and time-to-market make more and more sense to a PWN!

Limitless Mobile

Limitless Mobile is an FCC-regulated US wireless carrier focused on using its wireless carrier status, assets and capabilities as well as specialist wireless expertise and experience to enable technically advanced wireless propositions for enterprise and wholesale customers, both nationwide in the US as well as internationally.

Limitless Mobile serves a wide range of companies from start-ups to Fortune 500 entities, serving commercial and government markets, who seek access to e.g. US wireless carrier numbering assets, wireless core network as-a-service, roaming-as-a-service or specialist wireless NOC-as-a-service propositions or simply looking for a partner to provide strategic, technical or operational consultancy to maximise the potential of existing and new wireless opportunities.

Limitless Mobile has designed, deployed and is currently managing multiple Private Wireless Networks both in the US as well as abroad and continues to create innovative solutions for challenging holding back the development of the US wireless wholesale market.

If your company is planning to deploy a Private Wireless Network, we would love to hear from you at [email protected] to organize a call and share how we could help ensure a successful design, deployment and management of your Private Wireless Network!