The 3 Major Flaws of LoRaWAN

LoRaWAN has three undeniable flaws

  1. Nearly all uplink messages are unacknowledged (you won’t know if the message was ever successfully delivered)
  2. All gateways in range see all uplink traffic (not safe)
  3. LoRaWAN requires an enormous amount of bandwidth (tough to scale, culprit for ISM band traffic, subject to interference from other LoRaWAN gateways)

 

1. Nearly all uplink messages are unacknowledged

LoRaWAN has 1% Duty Cycle Limit for both end devices and the gateway (A duty cycle is the fraction of one period in which a signal or system is active. A period is the time it takes for a signal to complete an on-and-off cycle) In order to support the 1% duty cycle limitation for the gateway, all uplink messages are unacknowledged and uncoordinated, LoRaWAN is considered a “pure-aloha” scheme.

What is pure-aloha: “The idea is applicable to systems in which uncoordinated users are competing for a single channel (shared resource). ALOHA permits users to transmit any time they feel like. Collisions will occur and therefore colliding frames will be destroyed. However, if feedback is available on the destruction, then users will be made aware of their frames have not been transmitted (received) successfully  (1)

“Such a network has about 18% efficiency. This means that 82% of packets are lost when a LoRaWAN network is fully utilized. Since most messages are unacknowledged, the end node does not know its message was missed”(2). The Things Network also confirms this statement by stating “the capacity for downlink messages is even lower than for uplink messages, so don’t waste it.”

2. All gateways in range see all uplink traffic (not safe)

No explanation required.

3. LoRaWAN requires an enormous amount of bandwidth

see my previous post: LORA vs. Sigfox vs. Weightless-P

Sources:

1: Notes on the efficiency of ALOHA: http://www.csee.umbc.edu/~chettri/cs481/notes/NotesOnTheEfficiencyOfALOHA.pdf

2.Link Labs Blog: https://www.link-labs.com/use-cases-and-considerations-for-lorawan/

3. https://iotee.wordpress.com/2015/12/08/lpwan-technology-comparison/