"Texting without cell service" sounds like one need, but it really
bundles two very different jobs. One is communicating within
a group that's travelling together - a few friends who split up in
the forest, a family spread around a campsite. The other is reaching
out - messaging someone at home, or calling for rescue -
from somewhere with no infrastructure left.
The options below aren't a ranking. Each one does one part of the
problem well and barely touches the rest. For the wider picture -
including why your phone's GPS keeps working even when texting
doesn't - see
off-grid communication: what it is and how it works.
Wi-Fi or Bluetooth directly between phones
Some messaging apps can send directly between phones that are very
close together over Bluetooth or peer-to-peer Wi-Fi, with no tower.
This only works over very short distances - typically within a few
tens of metres, much less with obstacles in the way - so it suits a
packed crowd more than a group spread out on a trail. It also
depends on everyone running the same app with the right mode
switched on.
Two-way radios
FRS, GMRS or equivalent radios, depending on your region, give
instant voice communication when the group is close. Push a button,
talk, and anyone on the same channel hears you right away. No
pairing, no app.
But a two-way radio is a live conversation, not a message: if
someone isn't holding the radio or has the volume low, they miss it
and nothing is stored. No history, no map, no idea where each person
is. Range also depends heavily on terrain - one ridge between two
radios is enough to cut the link.
Nelos
This is the closest thing to "group texting without signal" in the actual sense of texting. Each person carries a small radio connected to their phone over Bluetooth. The devices talk directly to each other, and a repeater can relay for anyone out of direct range, forming a network that needs no outside infrastructure - suits short messages and location coordinates, not photos, voice or web.
Nelos gives you group messaging, direct messages, everyone's
latest location on an
offline map, and a "Need
Help" button that alerts the other members of your group. No
per-message fee, and you can start using it for free. The guide
LoRa Mesh vs Cellular Networks
compares the two kinds of network in more detail.
Satellite messaging
Handheld satellite messengers (for example Garmin inReach, Zoleo)
and the satellite messaging feature on some newer phones connect
straight to a satellite network instead of a ground tower. That lets
them send from places with no cellular infrastructure at all, and
more importantly, it lets them reach outside the group - a
relative in another region, or an emergency response coordination
centre via an SOS button.
The trade-off is a monthly subscription, a higher device cost, a
slower messaging pace, and the need for a relatively clear view of
the sky. This is not a way for a whole group to message each other
all day.
Ordinary messaging apps and their limits
Apps like standard texting, Messenger, or WhatsApp all need the
internet to send. When mobile data and Wi-Fi are gone, they stop -
the message sits in a queue and only sends once the phone gets a
connection back. Some services offer emergency satellite texting on
supported hardware and regions, but that's a narrow feature, not a
substitute for a stable group communication channel.
Choose by need, not by device
A group travelling together that just needs to message each
other and see each other's location: a LoRa mesh system
fills exactly this gap. Two-way radios are the cheaper option if you
only need voice at close range in open terrain.
You need to reach someone far away, or call for rescue from
somewhere remote: that's the job of a satellite messenger
or a PLB. LoRa mesh does not replace this part.
You're somewhere crowded where the network is overloaded
rather than absent: an internal channel between a few people
- LoRa, or direct Bluetooth messaging if the app supports it - can
keep you in contact when regular texts get stuck.
Many groups combine these: an internet app when there's signal, a
LoRa layer for the stretch with none, and a separate satellite
device for the ability to call for rescue if the trip needs it. The
guides
How to Communicate While Hiking Without Cell Service
and
Best goTenna Mesh Alternatives
put these directions side by side. If you go the LoRa route with
Nelos, Getting Started covers what
device you need and how to set up a team.