Wednesday, December 2, 2015

WiFi: Comparison of WiFi Direct vs WiFi Aware vs BLE vs Adhoc mode (802.11)

WiFi Aware - service discovery that helps setup WiFi Direct links.
BLE - service discovery and P2P connection.
WiFi Direct - P2P connection
WiFi Adhoc mode - basic P2P connection (legacy mechanism)

We will now differentiate between each of these protocol suites and their applications.

WiFi Aware vs BLE
- WiFi Aware has a longer range (because of wifi power limits)
- works with existing WiFi chips (protocol overlay - Phy is mostly the same)
- higher bandwidth than BLE (faster for gaming etc) - this is because it will use WiFi Direct once wifi aware discovers the service.

- WiFi aware works across brands of phone vs ibeacons which will work only on iPhones for e.g.

- Wifi will lead to higher power consumption though - even for service discovery over a longer range as compared to BLE.

What is the relationship between Wi-Fi Aware and Wi-Fi Direct?
(This part is an excerpt from WFA)
Wi-Fi Aware provides an efficient mechanism for always-on service discovery, whereas Wi-Fi Direct provides data connectivity among groups of devices. The technologies are complementary. Once an interesting service is discovered, a device can initiate a high-performance connection using Wi-Fi Direct for data transfer related to the service, e.g. sharing photos or playing a multiplayer game.

So how what was the legacy Adhoc mode about?
The legacy adhoc mode of connection was a preliminary mechanism for doing peer to peer connections with the WiFi protocol in the absence of an infrastructure (access point). WiFi Direct is an advancement of that mechanism, where if the MAC is capable, the clients can form a direct P2P connection as well as have an infra link by being connected to the AP. It is also designed to be scalable and faster than the legacy adhoc mechanism since grouping works more effectively. Typically, from what I remember with the testing on adhoc mode cards, IP assignment was static. With WiFi Direct, the group owner (GO) in the protocol typically acts as the DHCP server. Another difference is that the best level of security for adhoc networks was WEP, while Direct can do WPA2 [2].

Interesting research question to answer with these: How do they co-exist of interact or help make each other better?  Discuss with me.

Cite this blog post
G. Bhanage, Comparison of  WiFi Direct vs WiFi Aware vs BLE vs Adhoc mode,, 2015.