In order to support various innovative demand response programs, smart grid needs a wireless communication network with quality-of-service (QoS) support. This paper studies the issue of providing QoS in terms of packet delay, packet error probability, and outage probability to a large number of sensors and smart meters in a neighborhood area network of a densely populated urban area. We assume the network is based on the IEEE 802.15.4g Standard. Given that bandwidth is limited, we propose to divide smart meters into groups and each group will take a turn to access a shared wireless channel in a time-division-multiplexing manner. Within each allocated time duration, a group of smart meters will compete for channel access using a simple slotted Aloha protocol. We have developed an analytical model to quantify the QoS metrics. Through the analytical model, we can determine the minimum concentrator density that is required to support a given smart meter density. We have verified the analytical model through simulations. The results show that we need less than ten concentrators per km 2 to support a node density of 500 units per km 2 , while making sure that packet delay does not exceed 1.0 s, packet error probability is below 0.005 and outage probability is lower than 0.01.Index Terms-Concentrator density, neighborhood area network (NAN), quality-of-service (QoS), sensor, smart grid, smart meter.